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I just went 1500 miles. stock L98, 6spd. This was a sweet spot. 95 outside, cold AC inside.
I didn't see those highway 30+ mpg either until after I burned a prom, I think the new bin file had some better tuning than stock idk. Stock manifolds to H pipe straight duals to Corsa made a sotp noticeable performance boost. I didn't really check mpg before all that, mpg was not part of the hobby then, but it is now! Local driving is best high teens 14-18 or so.
Ok, I own a 1992 LT1 Automatic C4 Corvette Coupe . The car looks original as far as I can tell. I can say this being pretty certain that the rear gears were not changed. from the 2:59s they came with due to the fact of how lame it is off the line. The only mod that I have done to the car is installed a K&N air filter and cut a big square in the airbox for better breathing.
I find people on here that are stating they are getting from 27mpg up to almost 30mpgs from their cars. My car has a fresh tune, New wires 8.5MM MSD, New Coil, and Optspark W/vent all MSD. NGK plugs. The best I think I have come close to getting is around 23mpg. Why is my car eating up so much gas compared to everyone else that is posting. Does anyone have any idea how to improve the gas mileage without buying a 1979 pinto which I don't think got that good of gas mileage at the time
Mike
23 MPG is good as a combined average. My 1995 M6 is all stock and runs awesome... with 21 MPG combined average. Long highway runs are 28-29 MPG consistently, so I assume city driving is around 14-16. Many things affect fuel economy: driving habits / short trips, low ambient temps, warm-up (idle) time before driving, tire pressures, alignment, etc. Remember, your transmission was built before automatics got really modern and efficient so you can expect a few MPGs less than the M6 cars. I suggest you pull a few spark plugs and check their condition, to see if it's running rich or not. Anything else that could be choking off the engine, like a plugged cat? All the fluids (tranny & diff) are full and clean? How are the U-joints? (Looking at drivetrain losses here.) Also if your O2 sensors are original, they may be sluggish. Do these cars have AFR (air-fuel ratio) sensors? Something else to check... just a thought. Good luck.
Yes for me this is one of many hobbies. The fuel pressure regulator and filters were replaced. I am currently in RI took a road trip to see family and I let the car warm up reset the MPG I live in Upstate NY so the trip is just about 360 miles. I drove straight through with the cruise control at 73 mph using 91 octane fuel and at the end of the trip ended up with an Avg Mpg at 21.5 which to me really is not all that bad. I did not stop and there was no traffic.
The real reason for the post was just blown away by the people stating they were getting over 25mpg. I will be driving back to NY this Friday. I will fill up before I leave reset the trip and then fill back up once I get home and do the math. I will then report what I get. Thank you all for your input on this nonsense post
In my 87 I was at around 28MPG at one point, however I had to drive it literally like a grandma to get that. Even under normal driving its normal to get like 14-16 mpg in C4s. If you are meticulous in trying to barely touch the pedal everywhere you go and coast through lights you can get in the high 20s to 30. That's my experience anyway. As far as smiles per gallon, you're better off stomping it at the light
Ok, I own a 1992 LT1 Automatic C4 Corvette Coupe . The car looks original as far as I can tell. I can say this being pretty certain that the rear gears were not changed. from the 2:59s they came with due to the fact of how lame it is off the line. The only mod that I have done to the car is installed a K&N air filter and cut a big square in the airbox for better breathing.
I find people on here that are stating they are getting from 27mpg up to almost 30mpgs from their cars. My car has a fresh tune, New wires 8.5MM MSD, New Coil, and Optspark W/vent all MSD. NGK plugs. The best I think I have come close to getting is around 23mpg. Why is my car eating up so much gas compared to everyone else that is posting. Does anyone have any idea how to improve the gas mileage without buying a 1979 pinto which I don't think got that good of gas mileage at the time
I am surprised that so many are getting low mpg's. On my current cars '95 LT1 6M and '96 LT4 6M the original window stickers showed the EPA mpg to be 27 highway. Normally I can beat the EPA numbers by a couple.
It always seems to come up that if you look at mpg #'s you shouldn't be driving a sports car because you are not driving it hard enough to enjoy it. I have done several types of racing (autocross and drag strip) with my corvettes (and some "spirited street" driving), so I do like to push them too. However, If you have taken over a 1000 mile day in one you know that all 1000 miles are not a race and nearly all of it is just a steady cruise. Even in my 100 mile per day commute, most of it is highway and not a race either.
In short, I like the good performance, and I also like the good mpg from my Corvettes. I want it all.
I have owned 2 C4 Corvettes.
1st I bought from Albany N.Y.
2nd I bought in Boston Mass.
I drove both of them home. The first thing I did with both cars after picking them up was fill the tank.
Both rides were over 3 hours of non stop low traffic highway driving.
When I got home some 250-300 miles later both cars tanks were still registered as full.
2nd bar of fuel gauge was still filled in.
1st was a 1993 six speed.
2nd was a 1996 six speed.
on the trip from SC to WA the closer i got to 80 the better the mileage got. best on the DIC was 27.5. Quick math was giving me 27.2 so the DIC was not far off. around here in some mixed light traffic, short highway run are giving me about 24 on paper.
FWIW my gas gauge also doesn't read correctly even though the sender is new. i fill up at around a quarter tank which will be close to 11-ish gallons. i assume i need to tweak the rod in the tank slightly.
Took car to work yesterday and had to drive to see clients property with the drive being mostly highway. Filled with fuel on my way home from work and mpg was 28. I've been getting a bit over 20 mpg in mixed driving so very happy with the highway mileage.
That was just coming down from a 40 min ride at 65. The problem was believe it or not the rear wheels were out of balance. I thought they were a little off but I did not think it would make that big of a difference. I drove this same road same speed and never got over 22 before the balance.
Ok if that's highway mine is 18.5 in the city busy city and I have a 6 speed
I am. Even better actually, according to my HP Tuners scanner. LS1 swapped and tuned though.
Let me just add that that's ^ driving around in the suburbs, busy roads... Not driving on the highway.
On the highway I reckon I'd do around 40 mpg. My engine sits at around 1400rpm's at 60mph and I have a 4L60e behind it. Would be even better if my front-end was lower.
Nice thing about a six speed is the excellent fuel economy one can get.
I got over 27 average going to Arkansas from Michigan. At the pump and actual mileage. In 2019 I got over 33 mpg in the fuel economy run at Corvette Weekend at Eureka Springs, Arkansas.
Some newer ones over 40 mpg in a 100-110 mile course in the rolling Ozarks.
93 Ruby.
07-03-2021, 02:09 PM
