Question on mpg on 85 auto
Thread Starter
Instructor
Joined: Jul 2005
Posts: 202
Likes: 0
From: henderson nevada
Question on mpg on 85 auto
My 85 gets about 12-13 mpg in city (vegas) stop and go every 2 minutes! Think it get about 17 on highway. Sound right? Seems the car just slurps up a tank of gas too quick. My senor is off so when I am on reserve I actually have 7 gallons left. Does driving in D with out the square make a difference on gas, or should I be driving in D with square around town, or only on highway? Help, THX
Thread Starter
Instructor
Joined: Jul 2005
Posts: 202
Likes: 0
From: henderson nevada
WOW That is a big difference! Had the whole car gone over. 54K miles on it. New spark plugs, radiator flush new shocks, throttle body cleaned out, do not understand this gas milage!
Thread Starter
Instructor
Joined: Jul 2005
Posts: 202
Likes: 0
From: henderson nevada
Originally Posted by casinomgr
WOW That is a big difference! Had the whole car gone over. 54K miles on it. New spark plugs, radiator flush new shocks, throttle body cleaned out, do not understand this gas milage!
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by casinomgr
How much to do an 02 sensor check and then what happens???
Maybe someone else will have an idea, but I always thought that if your gas mileage is suffering- you need to replace the 02, the air filter and the spark plugs. You said you did the spark plugs already.
If after that you still have a problem, then i dont know what it could be... injectors? FPR? do you smell gas (as in a leak)? Hopefully someone else with more knowledge will jump in...
Drifting
Joined: Feb 2005
Posts: 1,592
Likes: 3
From: St Louis MO
I agree re O2 sensor replacement. They only cost about $20 and may give you some mpg gain. The D with the box around it is overdrive. For the most part, I would use it for driving in town or highway except maybe only in rainy weather. That may pick up a few mpg but not the numbers you are looking for.
Are you getting any "check engine" lights or codes?
Are you getting any "check engine" lights or codes?
Last edited by PierEagle; Sep 17, 2005 at 12:50 AM.
Instructor
Joined: Jun 2000
Posts: 233
Likes: 3
From: Tacoma WA
Not sure what the issue would be but my MPG is about 16-18 city and 24-27 Hiway---i have an auto with 3.07 rear--and 130K miles stock. my mililege starts realling sucking when my plugs get old--I know you had it gone over but I would just pull a plug and check---I have found lots of issues with Dealers and their attention to details--just pull one and look at it and check the gap on the plug--just a thought but that milage is really bad- even for stop and go.
best of luck.
Ron
best of luck.
Ron
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
The city mileage is normal, depends on traffic and such but its within reason.
Hwy mileage tells me you must have a tuneup done, O2 sensor especially needs replacing. Even if its fine and you just needed plugs/wires/cap/rotor, its still 20 years old.
Hwy mileage tells me you must have a tuneup done, O2 sensor especially needs replacing. Even if its fine and you just needed plugs/wires/cap/rotor, its still 20 years old.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
