well, having only owned 6 speed ls1s thus far, im pretty new to the auto world. anyway, i just bought it a couple weeks ago. ive been paying attention to my tach, and i noticed that on the highway going 55, my rpms are at ****** 1700-1800 i used to be able to cruise in 6th gear on the highway and do like 70 at as low as 1500 rpms (with my m6). i know this is probably a stupid question, but is an a4 cruising at 2000 rpms burning more gas than an m6 cruising at 1500 rpms?? i didnt know if the trannies/gear ratios had anything to do with how much gas youre actually burning. and lastly, what do u a4 guys cruise at on the highway to save on gas?? i felt like an 80 year old lady today cuz i was cruisin at 55 at 1700 rpms and getting passed by everyone!!! lemme know what u guys are doin...thanks

 

mine and most customers say they get 20-25 mpg stick cars and autos have different rear end ratios plus a t56 6 spd has two overdrives making rpm's lower

 

yea 6th in an M6 has a ratio of .5 compared that of 4th gear that has a .7 Its kinda like being in 5th in ur M6 also ur rear end gear has alot to do with it.

 

**** forget about MPG, slam that babie every chance you get!

 

if your are running at a higher rpm your are burning more fuel.. its that simple...and that rpm does sound about right... its' a draw back... but what do you do??? A4 not as fun as M6 but when it comes to shifting A4>M6.

 

What they all said. I still got 27 mpg on longs trips, and that was cruising at 80 with blasts over 100mph. That was stall only with stock 3.23s.

Try highway with 3.73s, I'm turning around 2500 to do 70 now.

 

You must have 3.23's or 3.42's. 2.73's will give you 70mph @ 1750rpm. You could probably find a used set cheap if you wanted to make the swap.

 

hmmm...i guess i have 3.23s...but i dunno for sure. what did 98 z28 a4s come with??

 

2.73's or 3.23's

Look at your door sticker, if it has a GU2 then it's a 2.73, if it's a GU5 then it's a 3.23

 

At 55 im at about 2400 rpm. I drove from Wichita,Ks. to Omaha, Ne on one tank of gas. with some in the tank....3100rpm all the way. I was impressed with the milage i got.