This is rediculous im getting 16 mpg on the highway. 95 z M6 with CAI, Granatelli MAF, Borla catback, and tb bypass. I have tried fuel system cleaner, did nothing. Im not driving hard at all, infact have to be exta gentle to get 16! Any ideas?

 

Does your oil have a fuel smell?

When was the last time you did an ignition tune up?

Still have cats? If so how many miles on them?

 

What gears? Those the only mods?

How old are the o2 sensors?

Any lights or codes being set?

Age of fuel filter?

Last time plugs/wires where changed?

Tire pressure?

Age of injectors? Could be a leaky one, do a leak test on them.

I can get that or better with mine lol.

 

60k miles on the car 3.42 gears original cat. Everything else im not sure about the age as i just got the car three years ago and didnt change any of it (always go that mileage) . I changing pluges wires cap rotor and coil this weekend. Should i change one thing at a time (injectors cat etc.) or just do it all and get it over with? No check engine lights on and the oil smells fine. Seems like it might be burning alittle rich but nothing to spark a problem i dont think.

 

maybe the IAC sensor has gone bad, i know a friend of mines did that and it read as if it was like 5* air temp so naturally the computer dumped a bunch of fuel in and it was runnning rich as hell. Should probably hook it up to a tech 2 and go through the system and make sure everything checks out

 

Don't you mean IAT (air temperature sensor)? Costs like $10 to replace so it couldn't hurt. However, a SES light would come on if it's too far out of range. Are you running 91+ octane?

 

Yes i am running 93 octane. If i had a cloged cat or bad sensor or injectors wouldnt that trigger a check engine light?

 

lol i would kill for 10mpg+ on the highway!

 

I wouldn't change the cap/rotor until it actually needs it. You may try swapping the MAF back to the stocker. Also, if you have a scanner, you could check your O2s and make sure they're working. Lastly, you really should change the fuel filter about once a year.

 

Do a tune up, plugs wires and fuel filter, change your oil too. I was getting 16-17 mpg, I shot up alot, getting like 24, could probably manage 30 if I kept my foot out of it for the whole tank, but every now and then I like to drive it like it was meant to be driven.

3 years is a long time to go without a tune up. Your probably on the original wires and plugs, too if it only has 60k on it and they gotta be hurting by now.

The car will probably be more responsive and might even feel faster after you change all that stuff.

 

I get about 16mpg in the city with my 97 Z-28 SS , just got the car about two weeke ago. Compared to my v-8 powered S-10 16mpg is a dream!

The s-10 has a built 350, with a TH-350 tranny, it gets about 6mpg max!

Chas

 

In regards to the V8 S-10 getting only 6mpg; ANY 350 short of a full racing engine w/4.56+gears or a 350 in a dump truck should get much better than 6mpg ! EVEN WITH A 3sp. TH-350 !
What have you got on that thing ? Enderle Injection ?
Even Nextel Cup NASCAR cars get around 4mpg, and that is at 180+mph with a 750hp engine !

 

No kidding. My last S10 had a 406/th350/3.23 gears and it still got 15 on the highway.

 

I bought the truck used, dont really know any specs on the cam or engine build. I know its a dog out of the hole, but past 3000 rpms, and the truck will scream and lay ya back in the seat. It has unreal power past 3000 and just acts like it wants to fly as the rpms go up!

I would think it has the wrong cam, and also the Demon 625 carb could use some tuning. If i were to keep the truck, i would check the cam, stall and rear end.

I guess i will sell the s10 now that i have the 97 Camaro.

Chas

 

Cant believe no one said O2's, thats a HUGE factor in your driving air/fuel ratio. CHANGE THEM, also my car gets 16 mpg city/highway mix, and 22 on 100% highway driving, so theres something SERIOUSLY wrong.

*edit ok someone asked about them, you need to check them...