M42 Gas Mileage Thread

[I8UR911]

27-28 with a 3.73LSD. Also have a Turner chip and COP. Relatively good considering....

[jrobie79]

28-29 4.10 LSD mostly highway with markD chip...was getting 31+ w/o the chip tho

[gearheadE30]

20ish city and 32 highway. 3.73 diff and a turbo. I believe I still have some work to do on my acceleration enrichment curves based on the city mileage, but it runs fine. Pre-turbo I was getting 26-28 highway with the 4.10.

[ma.jomaa]

I get 30mpg combined, m42 in a 1975 2002, all emissions components deleted, no cat, running a bit rich, headers+2.5" piping resonator+muffler, mostly going 75+ mph.

[Quadrajet]

With my first m42 with a lazy thermostat(opens early) on the island I got 26, on the freeway 29-30mpg.

With my current m42 with new thermostat, seems to run a little hot, I get 29-30 on the island, with 34 on the freeway. Last measured on a trip to Kirkland and back. 70-75 for peak speed.

4.10LSD, all other parts the same on the chassis.

[AE86]

23-25 City - 30-32 Highway : Average 26mpg

[InNeedOfBoost]

I average about 32 hwy and 28 city...cooler weather and switching to an e-fan made a big difference. I run semi rich too....I need to check my O2.

[Balleristic31]

Just got 25mpg on my last fill up with about 80/20 city/highway driving.