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What is your average mileage on a full tank?

SilveR1

New member
Location
Toronto
640 KMs or so (75% highway/25% city), but the city driving increases my fuel consumption by at least .5 L.

I have about a 90 km round-trip commute each day.
 

dub_guy

Ready to race!
Location
GTA
7.9L/100km over 18,250km.

Numbers are starting to get worse as I'm no longer doing the weekend cottage runs.

JB4 also just went on, so waiting to see how that affects things.

As for the comment above of 87 vs 91:
On 5,600km of 87 - 7.8L/100km
On 12,600km of 91 - 7.95L/100km
 

zero10

Ready to race!
I have a stock 2017 Golf Trendline 5-door with 5MT. I commute 125km daily, about 75% highway 25% city, highway driving is through low mountains in the BC interior.
Over the past 6000km I have averaged 7.2L/100km and can typically manage to fill up once per week (625km per tank) at just over 40L per fill (DTE usually says between 0-20km remaining).

Previously I made this commute in a 2010 Hyundai Elantra Touring 5MT, and it averaged about 8.3L/100km however it had a bigger tank so I wasn't seeing the fuel light an "0km" to empty weekly.

It's frustrating how small the tank is in the Golf. Even if I run it to 0km remaining I am only filling 46L. Upon refueling the DTE shows 720-730km but I never seem to get that far.

I have done a small comparison of 87 (10% ethanol) vs 91 (ethanol free) and on the 91 I was getting around 6.7L/100km instead of 7.2. Noticeably better but I attribute that more to the lack of ethanol than to the higher octane rating.
 

amiriten

New member
2017 5dr golf trendline automatic since 01/09/2017 and already at 23k. I have only fed it 87 octane with 85/15 city/hghw and average speeds of 120 on highway.
I get 6.5 and I do have a heavy foot in the city. My best stat was after my first oil change at 15k about 2 weeks ago when I achieved 860 km on a full tank of 52 liters.

Sent from my VS995 using Tapatalk
 

kri$han1

Passed Driver's Ed
Location
Toronto
I drive a mix of city and highway, slightly more in city. I've been getting around 450km per tank on 91 in a stock 17 GTI+PP. Had the car since August and that has been roughly the average point the empty like comes on.

Same. Picked 'er up In September, and I only run 91, as well.

I do mostly highway driving, but I have been routinely getting 600+ km per tank of 48L Regular. I imagine I can probably squeeze a few extra KM if I were to switch to premium\

I have just under 22K km on my 17 GTI

I think the opposite is true: lower octane tends to favor lower gas mileage (more efficiency), whereas those of us running 91 are getting a little less mileage. I'm usually around the 500km mark when the gas light comes on.

I notice this trend with my motorcycle as well; it feels more enthusiastic on 91, but it burns through the tank much faster than on 87. :confused:
 

Tsi7

Ready to race!
Location
Ontario, Canada
Technically 91 is more efficient as it's less prone to uncontrolled combustion (aka detonation), but the idea is that if the car doesn't require 91 you'll just have more fuel that is unburnt. I'm pretty sure that's how octane works... now I can't speak for the tsi engines and if the ecu compensates for the difference in octane rating, but judging that the 170hp rating for the 1.8t was acheived using 91, I assume the ecu compensates since we can run 87. I've only done one take so far, got 483 (8.6 L/100km) but that was mainly because I had some fun with the new car. This tank trip computer says 7.8 but I'm guessing that's a little optimistic. Driving is anywhere from 50-50 or 60 city 40 highway
 

Summons

New member
Location
Toronto
Technically 91 is more efficient as it's less prone to uncontrolled combustion (aka detonation), but the idea is that if the car doesn't require 91 you'll just have more fuel that is unburnt. I'm pretty sure that's how octane works... now I can't speak for the tsi engines and if the ecu compensates for the difference in octane rating, but judging that the 170hp rating for the 1.8t was acheived using 91, I assume the ecu compensates since we can run 87. I've only done one take so far, got 483 (8.6 L/100km) but that was mainly because I had some fun with the new car. This tank trip computer says 7.8 but I'm guessing that's a little optimistic. Driving is anywhere from 50-50 or 60 city 40 highway

Higher octane fuel detonates/knocks at a higher pressure and temperature than lower octane fuel. It also burns more slowly than low octane fuel at the same temp and pressure.

On an engine designed for 87, higher octane is likely a waste unless pushing the engine to extremes - by that I mean towing up hill on an old engine or such. In that case, the engine is working so hard, chamber temps climb, and the ECU can't do enough by enriching the mixture and adjusting timing to cool the temps to prevent detonation/knock.

If the engine is made for 91 and you feed it 87, you might get away with it if gentle and/or accept poor fuel economy. The ECU will dump extra fuel into the engine to prevent knock/detonation - the extra fuel acts as an octane boost, if I remember right, by cooling the charge (evaporate some more fuel and the phase change sucks up a bunch more heat) and over successive strokes, by preventing full combustion (due too rich) also cooling the chamber temps.

So in a turbo vs a normally aspirated engine of the same design (pretend you add a turbo to a N/A engine), the turbo is cramming more air in, raising the pressure, and when a turbo compresses the air it heats it up, so raises the temps as well, thus requiring higher octane fuel to prevent detonation and make sure the flame front is controlled as well.

On a side note that doesn't really apply to our tiny car engines, if the octane is way too high, you can burn your exhaust valves... This can happen in the typically huge aero piston engines. There, if the octane is too high for the engine, the flame front hasn't burnt all the fuel before the exhaust valve opens and you blow fire past the fragile valve edges... These engines have huge pistons - damn near paint can sized vs the pop can sized pistons cars typically use.
Cheers,
Eric
 
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