real world MPG after gear swap.

[notsonic]

i just changed from 3.23s to 3.73s in my three four. i know a lot of people want to know about the change in fuel economy (especially nowadays) so heres my results so far. ill update it weekly as i get more data, for a bit anyway.

so according to my trip odometer i went 327 miles on 13.36 gallons. thats 24.48mpg. which is a 2-4mpg improvement when i had the 3.23s. obviously everyone is wrong and just doesnt want you to have bigger gears so they can be faster than you.
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just kiddin. thats before correcting for the error from not tuning. (which i am doing this week. id rather blow $300 than have my mileage rack up so fast.)

so using a conversion factor of ~15% total mileage comes out to 278mi, and 20.8mpg. which is rougly 1 mpg worse than what id normally get. and this was pushin it, whereas i had been getting kinda bored with my car and wouldnt bother getting on it at all prior to the gear swap.

ill be interested to see how accurate 15% is to the real values after tuning. thoiugh itll be a mild performance tune as well, which could affect economy in one way or the other as well.

[Smoke Panther]

Re: real world MPG after gear swap.

I still get 26 MPG with a cam and 4.11 gears...with a proper tune. Oh well

[Pewter2K1]

Re: real world MPG after gear swap.

i usually average about 30mpg on the highway.... 4.10s and an auto... 20-25 around town depending on my mood... :)

and i too am cammed...

[95astrovan]

Re: real world MPG after gear swap.

dang...i get 27 on the highway, 19 average stock...

sounds like it's time for gears and a tune :naughty:

[RadRacer]

Re: real world MPG after gear swap.

I just did 360miles and gauge is still on 1/2 tank. They were all highway miles, and I have 3.73s and a 5-speed. I can pull low-mid 20's city driving no problem, haven't calculated highway mileage yet.

[ssms5411]

Re: real world MPG after gear swap.

I get around average of 23 thats highway/city. Thats with a A4 transgo shift kit, 3.73's , cammed, and tuned on my wideband with Hptuners. I don't granny drive it, so if I drove normal I think I would at least get 28-30 mpg. Also have about 200lbs off the car, so that helps.

[Stock98camaro]

Re: real world MPG after gear swap.

Define your guy's "highway" speed.


I know some consider 55 highway, while others consider 70 or 80+.

[Smoke Panther]

Re: real world MPG after gear swap.

Define your guy's "highway" speed.


I know some consider 55 highway, while others consider 70 or 80+.

I go whatever the speed limit is...that ranges from 55 to 65, in VA

[ssms5411]

Re: real world MPG after gear swap.

My highway speed is around 75mph to 85mph, speed limit is from 55mph to 75mph, depends on the area.

[Smoke Panther]

Re: real world MPG after gear swap.

^you'd improve your gas mileage by slowing down. I picked up 2 MPG when I stopped going 75, and started going 65

[zpwn06]

Re: real world MPG after gear swap.

I get 17-24 mpg, depending on the price of gas :)

[DAS BOOT]

Re: real world MPG after gear swap.

i usually average about 30mpg on the highway.... 4.10s and an auto... 20-25 around town depending on my mood... :)

and i too am cammed...

gonna have to call Bull**** on this one unless by highway, you mean your cruise control is set at 25 mph. We can argue all day long but we will never really know except e-thug ****s swing awhile.



Truth is some cars do get a little better mileage around town with gears. But highway you are almost always going to see a decrease because your cruising speed is going to be a much higher RPM.

This is almost always why manuals get better gas then most autos, because manuals usually have an extra gear, which is usually a more fuel efficent ratio. (check EPA numbers for autos and manuals for the last 20 years)


Now my 5-speed 3.8L stock, with a tune, with bolts ons, whatever probably never really did better then 30mpg, and that was babying the hell out of it to see what kind of milage I coudl get. I did see alot of high 20s.

Now to say an A4(which I find hard to believe to ever get 30 mpg), with a cam, which also makes it harder to believe, then to say one that is cammed and with 4.10s, its total BS.

[DAS BOOT]

Re: real world MPG after gear swap.

As for my 3.4L, I think this is funny. I think I calculated gas mileage at like 22 mpg, and another time at like 15mpg(noticed car was acting funny, ended up being bad o2s)


But I never really calculated what kidn of mileage it got because well... gas was cheap and I never paid attention to it. LOL

[Smoke Panther]

Re: real world MPG after gear swap.

gonna have to call Bull**** on this one unless by highway, you mean your cruise control is set at 25 mph. We can argue all day long but we will never really know except e-thug ****s swing awhile.

This is almost always why manuals get better gas then most autos, because manuals usually have an extra gear, which is usually a more fuel efficent ratio. (check EPA numbers for autos and manuals for the last 20 years)


Now to say an A4(which I find hard to believe to ever get 30 mpg), with a cam, which also makes it harder to believe, then to say one that is cammed and with 4.10s, its total BS.

Hey, smart guy. The 4th gear ratio in A4's is shorter than the 5th gear ratio in M5's

[LETZRIDE]

Re: real world MPG after gear swap.

I can get around 650km to a tank all highway and still not be completely empty (almost though) at about 114km/h on 100 highway

not sure what the mpg works out to be, but I do believe that it is close to 30?

thats with a full bolt on and 3.90 gears in an A4

city is a different story all togther...I average about 400-420 a tank now...

Just imagine what I would get if I did 100 all the time...

actually 70-80k is the best range for my set up as I only rev at 1500 rpm....