dump the chip unless it was custom made for the car by dyno tuning. My 85 stock was getting 26.2 on the freeway and 19-21 around town....automatic 3.07 rear end gears.
1985 mpg
Thread Starter
Instructor
Joined: Sep 2014
Posts: 139
Likes: 3
From: Roseville(outside Sac) CA
1985 mpg
I know its a muscle car and all but when you're 17 and pay for things yourself mpg is important. So my 85 Z51 is stock except for a chip and exhaust, transmission(automatic) is brand new, idle is set properly now, no vacuum leaks, everything works fine etc. Currently going 21 miles a day with 16 being freeway @ 70mph I'm averaging 15mpg is that typical or can it be improved? Edit: I only get on the gas when getting on the freeway because the on ramps I have to use are short.
Team Owner
Joined: Aug 2004
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From: Park City Utah
What are your other driving habits? Are you smooth/staedy on the throttle? Do you look (plan) ahead? Keep the RPM low? My '92 has a different motor, but my average mpg is in the 24 range.
http://www.fuelly.com/car/chevrolet/...m400CFI/129334
I'd consider getting rid of that chip and and putting a stock one back in.
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From: Athens AL
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Dump the chip.
I suspect you have an O2 sensor problem, they do not always give a SES light or engine code when they are on the way out.
I suspect you have an O2 sensor problem, they do not always give a SES light or engine code when they are on the way out.
Thread Starter
Instructor
Joined: Sep 2014
Posts: 139
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From: Roseville(outside Sac) CA
.
I'm pretty smooth when driving and easy on the gas the chip was on the car when I got it thanks for the advice I'll get rid of it my actual mpg is about 12 city and 21freeway which is pretty bad
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From: Fond Du lac Wisconsin
Bley49- If you are not leaking fuel out of an injector, then you are most likely running too rich. The computer should set your air/fuel ration at apprrox 14.7 to 1. Did you remove a spark plug yet? It could give you the clue that the engine is running rich. My 90 coupe with auto averaged 27.1 MPG on my last 2000 mile cross county trip. With a full tank, my computer shows a range of over 520 miles. What is your max range number with a full tank? Are your exhaust pipe tips looking sooty/ dark?
Thread Starter
Instructor
Joined: Sep 2014
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From: Roseville(outside Sac) CA
No leak but plugs are new saw nothing wrong there, tailpipes are clean but it seems the engine floods a little when's it warm so it takes longer to turn over when the engine has been ran in the past few hours
Team Owner
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From: Monaco
I haven't had my '93 (w-2.59 axle) long enough to get in any long road trips, but over the 1500+ miles I've logged locally it's averaging 18.5 mpg. Which is better than I've ever gotten from day one locally on my damned '03 4 cyl S10 run-about.....
