knta4dnu

Mods in sig. I originally had MadZ28 do the tune, then a couple years later had it dynoed. They were very impressed by how close the mail order tune was and barely changed anything.
My question is, if I have another mail order tune done on a 2nd ECM for economy on 87 octane instead of the now required 93, will I likely see an increase in gas mileage too? I have to use the car as a daily driver for now and I want to figure the total cost versus savings in the long run.

thanks

mzgp5x

I used MadZ. Also pcm for less. Now I do it myself. OBD2. LT1 edit version 2.2. Not popular with the masses. But has worked for me. I am quite modded. 97ss 383 D1 MM6 with lots of mods. Just converte to a single plane Gen 1 manifold. Anyway, I tuned the MAF for closed loop AFR mode cruz @ stoic (14.7:1). it works today. Untill I go to WOT. It pours fuel @ 12.8 AFR. Hope this helps. B.

ByByC5

I understand wanting better gas mileage on a daily driver, with 93 octane over $4.00/gallon.

But unless you present tune is very far off, (and it sounds like is not off) you will not see better fuel mileage running 87 octane in an LT1, with or without the hot cam.

Stock static compression around 10.5, (and don't remember the dynamic compression on that cam and a stock long block) It's going to be tough to get 87 to run without spark retard issues due to detonating.

I'm guessing (never tried it) the amount of timing you will have to pull out to get the motor to run without detonation, will negate the possibility of better fuel mileage.

I ran the hot cam (kit) in my car for many years, and put almost 100K miles on the motor with that cam. Made a great daily driver, and saw a lot of hwy miles too.
With an M6 trans an 4:10 gears, long tubes and all the bolt on stuff, I managed 13-14 city and 24-25 hwy mpg if I was careful, and drove responsibly On stock injectors (maxed out and higher fuel pressure)

I never had it on a dyno, but it made for a really quick car, and dependable fun car to drive. Thus my user name ^^

Keith