Tire Recommendation?

[dosjockey]

Well that's always the smart answer "go to the audio shop", that's great just listening to some head-banging rubbish on an 800 mile trip across Spain, just what I need at my age, and as far as insulation is concerned I have fitted that underneath all wheek arches, all through the boot, boot floor, parcel shelf and underneath the rear seat. Al totally unnecessary on a vehicle that can cost up to £37, 000 when fully loaded. Noise is not so much of an issue on super smooth European tarmac but on the amount of broken tarmac in the UK its not so great.

That doesn't make much sense at all.

When you walk into an audio shop, you are not immediately and unconditionally required to purchase an audio system and listen to music you don't prefer on penalty of death. You buy Dynamat there, or have it installed so it's done more quickly. As well, clearly the process is necessary if you want a quiet ride; regardless of the cost of the vehicle. It could be $300,000 and there's still no rule saying they have to insulate or deaden the car. Here, they clearly didn't. Doesn't matter how much sense it makes, the fact of the matter is that the car is largely uninsulated and undeadened.

If they were to do so, what's the point in buying an Audi? Even Mercedes offers an increased deadening option via their "Acoustic Comfort" package.

The deck lid, boot floor, and underneath the rear seats are reinforced areas of sheet metal. Those are some of the most rigid structures in the vehicle's body; less likely to cause the problem, but a good spot to turn some crashes into sharp thuds. As for the parcel shelf, I'm not sure what that's meant to accomplish. All I've got is some foam panel hanging from strings; hardly a source of road noise. I'm not sure what you mean by fitting insulation "under" the wheel arches, either. I'm also not clear on what you are using.

Insulation is not what you immediately need for road noise. You need deadening.

Vast, unsupported planes of metal are where that deadening needs to be. Large squares offset and applied to the roof and in foot-wells are choice, as are direct applications to the interior portion of wheel arches. On top of the deadening in that area goes insulation if you want it; the same goes for the roof; which only has a headliner protecting it. This helps with exhaust drone, as well; especially when applied with insulation on top.

Deadening increases the mass of the plane to which it is applied, and in the process lowers the resonant frequency of the steel (drops noise from being irritating to simply "being there"); and the larger the single sheets (around one to two square feet is ideal where reasonably possible), the more effectively they deaden the panel. You don't need to fully cover the panel, though. Just break it up with a few squares or rectangles. That alters resonance, which is where the road noise comes from to begin with.

The insulation on top keeps the reflections from amplifying each other inside the cabin by absorbing certain wavelengths; as many as possible, anyway. Since you can't just carpet the interior panels and glass with it, it's only going to partially have that effect. You'll still get reflections off glass and hard panels, but you're not going for audio performance; you're just going for keeping noise out of the cabin.

The structure of this car is stiff as hell. That means those shocks get sent right through the safety cage and cabin with little interference. It's going to be loud when they're using modern, thinner, more rigid steels; the same goes for if they don't laminate it as many times; which is where more expensive cars gain some of their cost. Cheap cars get one thicker sheet, and more expensive cars commonly feature several thinner sheets laminated together, which dramatically reduces resonance.

The audio shop is only a source and installation facility to save time. If it's easier to make $300 than it is to install it, just pay them and be done with it. If it's easier to install it than pay $300, buy it and install it yourself.

Of course, you may be relatively happy with what you already have. Maybe I'm misunderstanding your intended point.

 

[dosjockey]

It should be noted that sound deadening is necessarily heavy stuff. That's the whole point.

By not fitting so much, Volkswagen could well have saved around fifty pounds and, in this segment, that's a lot of performance gained simply by removing something. This may be why Golfs are largely left to be loud.

Maybe they're trying to stay as close to 3,000 pounds as possible in a world that keeps mandating heavy regulatory and safety equipment.

Sooner or later, they were bound to run out of ways to lighten the new equipment and shave mass elsewhere.

Just another way to look at it that doesn't include cheaping out. This could also be the cause of the cheapened materials in the MK8. Doesn't it seem to be the case that most of the "cost-cutting" on the MK7 and MK7.5 involved non-critical parts that added mass that wasn't required for function or enjoyment? Individually, they are light, but I wonder what would happen if you stacked up a factory amount of deadening alongside every last one of those parts...

I'll bet it would all tip the scales over a hundred pounds easily. Maybe VW wanted to get a little more effect than the engine alone provides as cars become heavier.

 

[E90 Skye]

Have had the PS4S on for about a week and I totally forgot what it's like to have some really good max performance summer tires. The grip is ridiculous, the car (i'm on stock suspension) turns in much quicker and more sure footed. With the pirellis I was getting some more understeer on initial turn-in until it sets into the turn.

Biggest things I've noticed with the PS4S (having only done 1 twisty road drive and a lot of highway/city)
-change of direction/turn in is very linear, stable, and quick
-a bit quieter (but I mean I'm comparing it to mostly worn PZEROs A/S+)
-wet grip is phenomenal
-incredibly smooth on smoother roads but on roads with very minute imperfections they are felt slightly due to the stiffer sidewall.
^ I know that sounds weird, but it's smoother on smooth/good roads than the PZEROs but on less perfect roads you feel tiny bumps a bit more than the PZEROs

So far I give these a huge thumbs up.

Other performance oriented tires I've used in the past are
Michelin PSS, PS2, PS A/S+
Continental Sport Contact 2, DW, DWS06
Pirelli PZERO A/S+
Sumitomo HTRZ III

And these take the top spot for me now away from the PSS. I was a big a fan of the Conti DW, even tho it had sloppy turn in it was just so comfortable, quiet, and retained dry/wet grip.

 

[vbrad26]

Have had the PS4S on for about a week and I totally forgot what it's like to have some really good max performance summer tires. The grip is ridiculous, the car (i'm on stock suspension) turns in much quicker and more sure footed. With the pirellis I was getting some more understeer on initial turn-in until it sets into the turn.

Biggest things I've noticed with the PS4S (having only done 1 twisty road drive and a lot of highway/city)
-change of direction/turn in is very linear, stable, and quick
-a bit quieter (but I mean I'm comparing it to mostly worn PZEROs A/S+)
-wet grip is phenomenal
-incredibly smooth on smoother roads but on roads with very minute imperfections they are felt slightly due to the stiffer sidewall.
^ I know that sounds weird, but it's smoother on smooth/good roads than the PZEROs but on less perfect roads you feel tiny bumps a bit more than the PZEROs

So far I give these a huge thumbs up.

Other performance oriented tires I've used in the past are
Michelin PSS, PS2, PS A/S+
Continental Sport Contact 2, DW, DWS06
Pirelli PZERO A/S+
Sumitomo HTRZ III

And these take the top spot for me now away from the PSS. I was a big a fan of the Conti DW, even tho it had sloppy turn in it was just so comfortable, quiet, and retained dry/wet grip.

Having had the AS3+ are the PS4S THAT much better for an otherwise totally stock daily driven GTI?
I currently have the AS3+ and love them, but a big part of deciding on all seasons was because I thought they would last a while longer.
I drive quite a bit, mostly in straight line stop and go, so I didn't think I really needed to go all out on tires.
But At the rate I'm going, the AS3+ may not get that much more mileage than I'm seeing people report from their PS4S.
I mean I definitely "use" my tires when I have the chance (I get a few good turns on my commute that I usually take advantage of hah).

 

[E90 Skye]

Having had the AS3+ are the PS4S THAT much better for an otherwise totally stock daily driven GTI?
I currently have the AS3+ and love them, but a big part of deciding on all seasons was because I thought they would last a while longer.
I drive quite a bit, mostly in straight line stop and go, so I didn't think I really needed to go all out on tires.
But At the rate I'm going, the AS3+ may not get that much more mileage than I'm seeing people report from their PS4S.
I mean I definitely "use" my tires when I have the chance (I get a few good turns on my commute that I usually take advantage of hah).

While I've had the AS+ I haven't yet tried the AS3+. I've heard those are about as close to a top end summer tire as all seasons can get. A friend of mine runs AS3+ on his e39 m5
So can't speak to the diff between the ps4s and as3+. When I was buying from costco the price difference was minimal.

 

[SouthFL_Mk7.5]

Been daily driving for a few days now on a set of 220tw Pirelli P Zero. This is a dated tire design as it first came out in 2007, but I must say, it’s still a great tire. I’ve used the set for a couple track days, where they performed well with decent grip, predicable manners and without getting greasy.

A couple days ago I switched them over to daily driving duty and they are comfortable, relatively quiet and offer all of the performance that I can demand from them on the street. At 220 UTQG, I don’t expect them to last as long as a 300+tw tire, but at a decent price (got ‘em on sale) due to their time on the market, they’re worth a look, especially if cold weather use isn’t a priority.

 

[vbrad26]

While I've had the AS+ I haven't yet tried the AS3+. I've heard those are about as close to a top end summer tire as all seasons can get. A friend of mine runs AS3+ on his e39 m5
So can't speak to the diff between the ps4s and as3+. When I was buying from costco the price difference was minimal.

Ah my mistake.
If I swap out the all seasons for a dedicated summer tire I will be looking at the Indy 500 ot the Conti Extreme Contact I think...

 

[amsr]

I just replaced the stock Pirelli P7 cinturato with Michelin AS3+ on stock Austin rims. Wheel spin on launch is gone and turn in is more crisp. Grip is clearly better in dry. Ride quality over small bumps is worse and mpg is worse. Also they are noisier in general and have this weird oscillating noise at 60-75 mph on smooth pavement. They sound like the cupped runflat Bridgestone tires I had on my BMW, although not as bad. Does anyone know if this goes away? I do like them, but the noise is annoying.

 

[fuelboss]

That doesn't make much sense at all.

When you walk into an audio shop, you are not immediately and unconditionally required to purchase an audio system and listen to music you don't prefer on penalty of death. You buy Dynamat there, or have it installed so it's done more quickly. As well, clearly the process is necessary if you want a quiet ride; regardless of the cost of the vehicle. It could be $300,000 and there's still no rule saying they have to insulate or deaden the car. Here, they clearly didn't. Doesn't matter how much sense it makes, the fact of the matter is that the car is largely uninsulated and undeadened.

If they were to do so, what's the point in buying an Audi? Even Mercedes offers an increased deadening option via their "Acoustic Comfort" package.

The deck lid, boot floor, and underneath the rear seats are reinforced areas of sheet metal. Those are some of the most rigid structures in the vehicle's body; less likely to cause the problem, but a good spot to turn some crashes into sharp thuds. As for the parcel shelf, I'm not sure what that's meant to accomplish. All I've got is some foam panel hanging from strings; hardly a source of road noise. I'm not sure what you mean by fitting insulation "under" the wheel arches, either. I'm also not clear on what you are using.

Insulation is not what you immediately need for road noise. You need deadening.

Vast, unsupported planes of metal are where that deadening needs to be. Large squares offset and applied to the roof and in foot-wells are choice, as are direct applications to the interior portion of wheel arches. On top of the deadening in that area goes insulation if you want it; the same goes for the roof; which only has a headliner protecting it. This helps with exhaust drone, as well; especially when applied with insulation on top.

Deadening increases the mass of the plane to which it is applied, and in the process lowers the resonant frequency of the steel (drops noise from being irritating to simply "being there"); and the larger the single sheets (around one to two square feet is ideal where reasonably possible), the more effectively they deaden the panel. You don't need to fully cover the panel, though. Just break it up with a few squares or rectangles. That alters resonance, which is where the road noise comes from to begin with.

The insulation on top keeps the reflections from amplifying each other inside the cabin by absorbing certain wavelengths; as many as possible, anyway. Since you can't just carpet the interior panels and glass with it, it's only going to partially have that effect. You'll still get reflections off glass and hard panels, but you're not going for audio performance; you're just going for keeping noise out of the cabin.

The structure of this car is stiff as hell. That means those shocks get sent right through the safety cage and cabin with little interference. It's going to be loud when they're using modern, thinner, more rigid steels; the same goes for if they don't laminate it as many times; which is where more expensive cars gain some of their cost. Cheap cars get one thicker sheet, and more expensive cars commonly feature several thinner sheets laminated together, which dramatically reduces resonance.

The audio shop is only a source and installation facility to save time. If it's easier to make $300 than it is to install it, just pay them and be done with it. If it's easier to install it than pay $300, buy it and install it yourself.

Of course, you may be relatively happy with what you already have. Maybe I'm misunderstanding your intended point.

It is Dynamat that has been fitted to the boot wheel-well, Internal wheel arches and under the rear seats. I also removed the wheel arch covers from all four wheels and fitted Dynamat to all exposed areas. It certainly made a difference, however........... I came from a MK7 GTI that for 3 years was a relatively quiet car with no intrusive cabin noise. Unfortunately this car was written off by a white van man on his mobile phone while travelling in southern Portugal. That car was replaced with a MK7.5 GTI and that is when very intrusive cabin noise became the issue. The difference in cabin noise levels between a MK7 and a 7.5 is very noticeable despite being on the same tires (Goodyear eagles). Where you live in Florida you may have generally smoother roads compared to what we have in the UK, where roads here are in generally poor condition. If you hit a stretch of super-smooth tarmac then of course the cabin noise is greatly reduced and I have no complaint but on many surfaces, particularly British motorways the noise intrusion can be very tiresome on long runs.

When the car was replaced in 2018 I actually purchased a Golf 1.5 TSI EVO. Great car, very comfortable but very intrusive noise from the rear. The VW dealer actually changed the rear wheel bearings because even master technician & service manager believed it was bearing noise, so that shows how noticeable the noise was. I then tested the new Highline version and that was also the same. On the same day I drove a usd GTI MK7 and guess what, far quieter, in fact a totally different car in terms of road and cabin noise. Having driven 3 MK7.5 cars I can say that without doubt they show far more cabin noise than their predecessor.

You say "the fact of the matter is that the car is largely insulated and undeadened". It certainly appears so but dont you think for the price of this vehicle, that more attention could be given to sound levels? The GT, and particularly the GTI & GTD is not just cars for the "boy racers", they are actually performance cars that can be used for day to day driving, commuting, family use etc and by people of various ages. For those who subscribe to the notion of "pumping up the volume", I would say, is that the best or only option?. Of course not, VW should have paid more attention to sound deadening to improve the cabin noise but we all know they would not do that if it will affect fuel consumption figures. Regarding parcel shelf - I just glued some egg-box foam sound insulation under the shelf. Whether that had any benefit I could not say but at least is stopped the rigid shelf from bouncing up and down over pot-holes.

I have just received the "balancing damper" as suggested by Golfdave. This will be fitted next week so I will soon give my opinion of what this can do, if anything, to reduce resonance etc. I dont see much enthusiasm for owners fitting this part but will give it a go as its not a very expensive item.

 

[dosjockey]

It is Dynamat that has been fitted to the boot wheel-well, Internal wheel arches and under the rear seats. I also removed the wheel arch covers from all four wheels and fitted Dynamat to all exposed areas. It certainly made a difference, however........... I came from a MK7 GTI that for 3 years was a relatively quiet car with no intrusive cabin noise. Unfortunately this car was written off by a white van man on his mobile phone while travelling in southern Portugal. That car was replaced with a MK7.5 GTI and that is when very intrusive cabin noise became the issue. The difference in cabin noise levels between a MK7 and a 7.5 is very noticeable despite being on the same tires (Goodyear eagles). Where you live in Florida you may have generally smoother roads compared to what we have in the UK, where roads here are in generally poor condition. If you hit a stretch of super-smooth tarmac then of course the cabin noise is greatly reduced and I have no complaint but on many surfaces, particularly British motorways the noise intrusion can be very tiresome on long runs.

When the car was replaced in 2018 I actually purchased a Golf 1.5 TSI EVO. Great car, very comfortable but very intrusive noise from the rear. The VW dealer actually changed the rear wheel bearings because even master technician & service manager believed it was bearing noise, so that shows how noticeable the noise was. I then tested the new Highline version and that was also the same. On the same day I drove a usd GTI MK7 and guess what, far quieter, in fact a totally different car in terms of road and cabin noise. Having driven 3 MK7.5 cars I can say that without doubt they show far more cabin noise than their predecessor.

You say "the fact of the matter is that the car is largely insulated and undeadened". It certainly appears so but dont you think for the price of this vehicle, that more attention could be given to sound levels? The GT, and particularly the GTI & GTD is not just cars for the "boy racers", they are actually performance cars that can be used for day to day driving, commuting, family use etc and by people of various ages. For those who subscribe to the notion of "pumping up the volume", I would say, is that the best or only option?. Of course not, VW should have paid more attention to sound deadening to improve the cabin noise but we all know they would not do that if it will affect fuel consumption figures. Regarding parcel shelf - I just glued some egg-box foam sound insulation under the shelf. Whether that had any benefit I could not say but at least is stopped the rigid shelf from bouncing up and down over pot-holes.

I have just received the "balancing damper" as suggested by Golfdave. This will be fitted next week so I will soon give my opinion of what this can do, if anything, to reduce resonance etc. I dont see much enthusiasm for owners fitting this part but will give it a go as its not a very expensive item.

I think they did well for the price. By the time all was said and done, I paid about $25,000 for my GTI brand new a couple of months ago.

I may not like the dim-witted response times of... Well, everything in the vehicle, but that's baked in deliberately. You're getting a hell of a lot of car with the GTI. The interior alone punches nearly $20,000 above it's weight, the ride quality/handling balance eclipses some cars nearly twice it's price, as well. Something had to give, and as things get more expensive over time, they will have to keep trimming the fat. On paper, this car should be more expensive than it is. The Golf needs to be pushed up market to prevent terminal cost-cutting.

Regardless, if all that is at the expense of some sound insulation, it's easy enough to fix.

You can see the struggle they had when designing that interior just by looking at the bottom of the B pillar, where the trim itself is about as thick as a trash bag. I wouldn't be surprised if the carpet insulation has been decreased over time as well, because that car has been at the bleeding edge of it's price point for years now. Eh. Minus the uncooperative drive-train, I feel like I got more than what I paid for. If I liked the way it drove, I'd probably call it the best value in the motoring industry; and even though I don't... It's damned close to that suggestion anyway; a severely grudgingly awarded trophy.

I'm assuming you used the correct Dynamat Xtreme? It's the messy rubber stuff commonly sold with a foil top layer, though sometimes you can get it black; not the foam though. The foam is a different product with a different purpose. The Xtreme winds down the "noise" to tolerable frequencies. The foam (Dynaliner) helps absorb reflections and adds a bit of actual acoustic insulation.

You apply the butyl rubber deadening sheets to the metal, and then over that you apply any foam (Dynamat or other) insulation/absorption material you want.

It's important to hit the firewall where possible and at least the front floor pans; ideally with at least one unbroken sheet bridging between the panels. As noted, the rear areas are some of the most reinforced in the whole vehicle. It's important to cut down on road noise back there (you're in a one-box car with waves just bouncing around willy-nilly), but overall resonance is still coming from the "problem areas" like those floor pans and the roof.

You may be able to improve the rear a bit more if you haven't fit insulation back there yet. Deadening makes a massive difference, but insulation does help. Taking it to a higher level would involve deadening the doors, or sealing cavities in the doors (just covering up holes). I know I'm going to see what I can get out of mine soon.

 

[fuelboss]

I think they did well for the price. By the time all was said and done, I paid about $25,000 for my GTI brand new a couple of months ago.

I may not like the dim-witted response times of... Well, everything in the vehicle, but that's baked in deliberately. You're getting a hell of a lot of car with the GTI. The interior alone punches nearly $20,000 above it's weight, the ride quality/handling balance eclipses some cars nearly twice it's price, as well. Something had to give, and as things get more expensive over time, they will have to keep trimming the fat. On paper, this car should be more expensive than it is. The Golf needs to be pushed up market to prevent terminal cost-cutting.

Regardless, if all that is at the expense of some sound insulation, it's easy enough to fix.

You can see the struggle they had when designing that interior just by looking at the bottom of the B pillar, where the trim itself is about as thick as a trash bag. I wouldn't be surprised if the carpet insulation has been decreased over time as well, because that car has been at the bleeding edge of it's price point for years now. Eh. Minus the uncooperative drive-train, I feel like I got more than what I paid for. If I liked the way it drove, I'd probably call it the best value in the motoring industry; and even though I don't... It's damned close to that suggestion anyway; a severely grudgingly awarded trophy.

I'm assuming you used the correct Dynamat Xtreme? It's the messy rubber stuff commonly sold with a foil top layer, though sometimes you can get it black; not the foam though. The foam is a different product with a different purpose. The Xtreme winds down the "noise" to tolerable frequencies. The foam (Dynaliner) helps absorb reflections and adds a bit of actual acoustic insulation.

You apply the butyl rubber deadening sheets to the metal, and then over that you apply any foam (Dynamat or other) insulation/absorption material you want.

It's important to hit the firewall where possible and at least the front floor pans; ideally with at least one unbroken sheet bridging between the panels. As noted, the rear areas are some of the most reinforced in the whole vehicle. It's important to cut down on road noise back there (you're in a one-box car with waves just bouncing around willy-nilly), but overall resonance is still coming from the "problem areas" like those floor pans and the roof.

You may be able to improve the rear a bit more if you haven't fit insulation back there yet. Deadening makes a massive difference, but insulation does help. Taking it to a higher level would involve deadening the doors, or sealing cavities in the doors (just covering up holes). I know I'm going to see what I can get out of mine soon.

Today I went to the local Audi Dealership an picked up this so-called "balancing damper". I dont know if you have fitted this but its 6 inches in length and weighs 1lb 8oz. From what GolfDave has written, it has cut out a lot of resonance and so I thought I would give it a try. I am having it fitted on Tuesday 17th March and will give my view on what if any difference it will make. Interestingly while at the dealer I had an opportunity to drive the Audi A3 Sportback. It was a 2019 model with a 15 TSI engine and 18 inch wheels. For the first 20yds of driving off the forecourt I though this feels nice, but that was it. Once onto the road and irrespective of speed it was the worst car have have ever driven. I drove over what we would call country roads that were a mixture of good, bad and ugly. I then took it onto a main A road. the cabin noise, the tyre noise, the hollow tone that irritates me was far in excess of what I have in the GTI. Even at 10/15mph there was this hollow booming noise at a very irritating frequency. The dealer had given me the car to drive for an hour or so but I was back in the dealership within 10 minutes. Damned awful noise. The cabin noise was pretty much as I had experienced on the Golf 1.5 GT Evo and on the Highline version and so it appears to be right across, not only the Golf but the A3 as well, which of course is expected as they are almost one and the same car.

My GTI may not be as quiet as I would like but after the Audi drive today I dont think I will complain too much about my car. Perhaps my fitting of the Dynamat Xtreme (yes, it was the extreme) did make a difference after all. I drove home with a smile on my face realizing that my car was far quieter than an A3. Just need to try a MK8 at some time soon. My view on that little lump of metal to follow next week.

PS I would be interested to know what model you have.

 

[dosjockey]

Today I went to the local Audi Dealership an picked up this so-called "balancing damper". I dont know if you have fitted this but its 6 inches in length and weighs 1lb 8oz. From what GolfDave has written, it has cut out a lot of resonance and so I thought I would give it a try. I am having it fitted on Tuesday 17th March and will give my view on what if any difference it will make. Interestingly while at the dealer I had an opportunity to drive the Audi A3 Sportback. It was a 2019 model with a 15 TSI engine and 18 inch wheels. For the first 20yds of driving off the forecourt I though this feels nice, but that was it. Once onto the road and irrespective of speed it was the worst car have have ever driven. I drove over what we would call country roads that were a mixture of good, bad and ugly. I then took it onto a main A road. the cabin noise, the tyre noise, the hollow tone that irritates me was far in excess of what I have in the GTI. Even at 10/15mph there was this hollow booming noise at a very irritating frequency. The dealer had given me the car to drive for an hour or so but I was back in the dealership within 10 minutes. Damned awful noise. The cabin noise was pretty much as I had experienced on the Golf 1.5 GT Evo and on the Highline version and so it appears to be right across, not only the Golf but the A3 as well, which of course is expected as they are almost one and the same car.

My GTI may not be as quiet as I would like but after the Audi drive today I dont think I will complain too much about my car. Perhaps my fitting of the Dynamat Xtreme (yes, it was the extreme) did make a difference after all. I drove home with a smile on my face realizing that my car was far quieter than an A3. Just need to try a MK8 at some time soon. My view on that little lump of metal to follow next week.

PS I would be interested to know what model you have.

I've got a 2019 GTI, North American specification. In NC, not FL; and our roads are absolutely horrid.

Never seen that specific part in relation to this car, but mass dampers are used in many industries, and indeed vehicles. That part may be for isolation instead; I don't know.

Adding mass works, though. It's doing the same thing Dynamat Xtreme is doing, but to a much more effective degree. Quite a few common shocks and vibrations just don't have the energy to move mass beyond a certain point that you can actually create, so you add as much as reasonable on the most vibration-prone area of the assembly; on a car, that's generally on a rotating assembly or around some input or output shaft.

They're great around differentials and driveshafts. You just put a lump of something heavy in the right place, and it quiets things down and reduces vibration. Here's an example of a factory-fitted damper that relies on increasing mass, from a Discovery II. Found this on Google instead of going outside LOL:

It's the big steel yoyo on the left of that stainless cable. It does absolutely nothing aside from sitting there and being heavy; but that's enough. They've got it attached directly to the drop-out third at the pinion shaft input. I don't remember how heavy the things are, but you certainly wouldn't want anyone throwing one at you. Notice it's actually got a safety wire from the factory. That's a high vibration area. Never seen one come off, though.

Your specific part may be meant for isolation instead of actual mass damping. I'm not sure, as I've never seen it before.

If it's using mass, it just needs to have whatever amount they require to tune the resonant frequency of the sub frame where they want it. If it's using isolation, those bushings may be different than what's there from the factory. I haven't even looked under my Golf yet. Just got it new a couple of months ago.