GTATIME

Hello ls1tech, okay so I have a 2000 z28 vert' A4 and I get about 11 miles to the gallon and as far as I know its stock but I do have a very small oil leak I get a little over 200 miles to the tank anybody have an idea why I get such bad mileage? I do drive fast every now and again but I don't think it should get crappy mpg just because of that

farmington

iTrader: (14)

I probably get around 17 in the city even with my mods.

FirstYrLS1Z

iTrader: (4)

https://ls1tech.com/forums/new-ls1-o...0-low-mpg.html

Chris25

iTrader: (1)

Has the routine stuff been replaced like Fuel filter,plugs,wires,air filter also is it throwing any codes ? Maybe a bad O2 sensor?

MysticA4Z28

If you get 11 mpg how are you getting over 200 miles to a tank? Lol

These are only 16 gallon tanks IIRC

CO99Z28Vert

iTrader: (30)

I miss getting over 20 in my last car, this new setup with the 427 gets about 8-10 depending on how you drive lol

MysticA4Z28

Even a setup like that should get over 20 mpg on the highway

01ssreda4

iTrader: (96)

I got about 20 or a little over when I was near stock. If you are in the low teens you got a bad sensor, probably MAF or 02s. If you're getting over 200 miles to the tank, you're math is wrong somewhere.

mrvedit

^^^ +1. Exactly right.

thunderstruck507

iTrader: (18)

Fill up the car, reset trip odometer. Drive the car through at least half a tank or more. Refill car (preferably at the same station/pump as before if possible). Divide miles on odometer by gallons used.

Past that, some scanning or routine maintenance will rule things out. Front O2 sensors or MAF sensor typically being the most common culprits. Clean the MAF first since that's easy with spray cleaner.

Don't be surprised to be getting mid teens if it's all city or stop/go driving and high teens low 20s highway. Especially if you hot rod it around much.

alex722607

iTrader: (4)

If you get 11, that is pretty bad. Any SES codes? My gen1 SBC block is crap and I get around 15-16 city (and I am beating the crap out of it while I still can, lol)

axekick

iTrader: (18)

This will be off if your tire/gear settings are off in the tune. Make sure your speedo is accurate. If it's not then you have to account for that in your mileage calcs.