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I've been averaging about 13 around town. The car has an intake and conservative tune. Yes, I stab it from time to time, but I still think my consumption is excessive. What are most of you averaging around town? Possible cause of excessive fuel burn? The tuner did set the AF slightly rich, but this is kind of ridiculous.
I average 18-19mpg around town but I don't "stab it from time to time". There's to much traffic congestion in our little community.
The little time I spend in town is driving to/from our favorite mountain range going from 5200-7000 ft altitude and lots of challenging mountain curves. Average there is about 22-24mpg unless the tourists are in town.
13 mpg is certainly kind of low considering the fact that your mods aren't exactly radical. Initially I started out with a Blackwing, tune, and an Xpipe and my mpg was closer to 20.I would check back with the tuner and maybe swap your plugs.
Damn, and I thought mine was bad. LOL I just recently did a cam swap on a 117K motor, LT, X-pipe, ported tb and bumped the cr up a tad. No dyno tune at the time just on the street and I'm getting roughly 18-20 around town w/ a stomp here and there but nothing serious. Once tuned maybe I'll get a little more but if not, no big deal. I'll stop complaining about my mileage now.
I'm using the DIC. I verify it with actual mileage when I fill up. I used Next Level Performance here in Orlando. Yes he has a GREAT rep and knows what he's doing. I've got just over 27K on the motor. It has brand new plugs and wires too.
Originally Posted by skyavonee
1) How are you measuring the 13 mpg number? Manually or through the DIC? The DIC isn't especially accurate.
2) What were you averaging before the tune?
3) Does your tuner have a good reputation among the local Corvette community or is he just a semi-random guy you found?
4) How many miles on your engine?
Assuming the 13 mpg number is correct, my guess is your partial throttle A/F is too low, but it's just a guess.
Just throwing this out there. I lost an O2 sensor in my '90 and the mileage went to heck, but IIRC it ran bad too. Cheap O2 sensors are akin to throwing away money.
I'm getting around 19mpg driving around town, not stop and go rush hour driving though. Last tank even included a dozen or so laps of track touring and still pulled 19 and change (offset by the highway to and from the track most likely).
I'll get an idea for highway mileage next month when I take off for vacation.
This may be obvious, but the longer you sit at red lights or warm your car up in the morning or run with the a/c on while parked will all greatly bring down your gas mileage!
Seems low.. do you have access to a scanner of some sort? your LFT's and SFT's will tell you if its tune issue. Mine is in the 17-18 mpg in the city with the occasional stabbing.