hey guys i was wondering if anyone could tell me what they were getting mileage wise out of your 93 z28 six speed, i am not a LT1 expert but i heard they changed fueling systems soon after the new model and was not sure if this affected the mileage any between the years, i am really wondering highway mileage numbers, if you have mods just list them so i can guage as what i have done to my car, thanx for the help!!!

 

on the highway i get about 18 at 65mph and about 14 at 80mph, city driving like 2

 

I've never tried to calculate it because the gear ratios are different which throws off the speedometer so the results wouldn't be accurate.

I can tell you the mileage of the Danger Ranger listed in the sig though - 16.5 mpg

 

You are also modified to the hilt!

I get about 22mpg mixed.

 

before i switched to 3.73s, i would get around 20 on the highway and 16 in town. Most of tanks would average about 260-280 miles.

 

My 93Z A4 (stock, sort-of) gets 20~24 highway... I have heard that M6 gets around 24~28 highway..

 

i am actually going to be swapping the entire drivetrain into my 76 which is comparable weight, it will have 3.42's with about a 27" tire, the main thing is my buddies 95 z m6 has full bolt ons, ignition box, tune, 4.10 gears and so on and gets 28 MPG on the highway, and the 93's i heard got worse is this because they went to mass air flow or is there no difference and i am just dreaming this up, thanx for all the input so far!!!

 

18-23 city 27-29 hwy with air on. 97 eng.95 Ta body,94 pcm,all bolt on mods 52mm tb,headers,smog pump deleted from pcm some a/f tuning

 

well i did a little searching and found that the 93's were still MPFI and in 94 they went to SPFI which is superior at least for mileage, what would eb involved in converting a 93 MPFI motor to a later SPFI besides the obvious ECU??

 

Intake Manifold and Fuel Rail are differnet i believe, besides that, maybe fuel lines??

 

no sensors or anything like maf? sorry i am not familiar with these systems right now, i am trying to get educated!!!

 

The 1993 camaro has speed density tune, no maf. Also I do believe the O2's are different, in 93 there is a removable chip in the computer to tune it, in 94 and up people use the hypertech or other programmable tuners. If you want to convert a 93 to 94, I do believe that the 94 has a little bigger injectors, different fuel rail, the throttle body does not have the kick down on it for the automatic transmission like the 93, the 94 is electronic trans. You would have to get a new wiring harness for the motor and maybe a few different sensors that i forgot. My 93 z gets around 17 mpg and that is mostly around town, if I beat on it it goes down around 11 mpg, that was before the converter.

 

Another reason why I don't try to calculate mileage

 

28 hwy was my best 96 M6, driving 500 miles from lower new york to michigan through canada

 

The 93 T56 has different, lower gearing than the 94+ T56 in all gears but 4th. The 6th gear is the biggest difference at .62 instead of .5. This is like having a 4.00 rear with the stoc 93 3.23's vs the later 94+ T56 3.42 combo. So the higher RPM in 6th on the highway can affect mileage slightly as well.

I just put a 93 M29 T56 in my 95 TA, and love it! Its like having around a 3.82 rear (average).