Gas milage

[alexhouston]

This past weekend I took the Riviatta on the road to the ranch for the first time. I typically take my truck but this time I opted to find out if my car could get the 30mpg some were saying they get. The best I got was 24mpg on a 120 mile straight highway ride at 65mph with few slowdowns. This really a little better than I had originaly expected.

What milage do the rest of you get on the highway?

[Reatta45]

I would think your mileage is about right?. On my ?91 I have always got 20 -21 MPG for years. I can make it use more but that is the typical it has ever got?

Although I have read and heard fantastic claims on all kinds of things. KennyV.

[Guest DTerry]

I took a 1422 mile trip last weekend to a high school class reunion - I won't say how many years, but a lot of folks won't believe people live that long. Overall average including city driving around Texarkana was 28.9 calculated. It was a disappointment, because it previously has returned 31+ on road trips. Had a slight headwind in both directions (how do it know?), but I wouldn't think it was enough to cause that much difference. The trip data showed 27.8, which was also surprising, because it has always been within half a mile per gallon of real life before. Suppose the new tires could cause a difference? Most of the trip was in daylight with the headlights retracted, cruise set at five over the limit.

Also received a warning of low refrigerant about 200 miles from home. Guess my A/C repair (compressor, accumulator, expansion valve) wasn't totally successful. I'll have to seek professional help now for a leak check.

[JWC]

My 89 gets any where from 28 to 32 and the 90 got 36 mpg on the way to and from the Reatta homecoming in Lansing, doing just over 70 mph I was really surprised.

Why such a big spread in mpg in these cars? My 89 has 170,000 miles and the 90 only has 56,000 miles

[manikmekanik]

The '91 Reattae have a higher final gear ratio, for better take-offs, this reduces fuel economy.

Still, I got 29 MPG on our recent trip to the Reatta Homecoming. This was due to 1+ hour in 5-20MPH traffic jam thru Chicago. I kicked it up a bit thru the rest of the trip, and made it within the (6 hour), prescribed time. I can't give an average speed, but I was clippin' along the Indiana toll road, (following a state trooper to a call, at a distance), in the 3-digit range, for over 45 min.

He eventually exited, near the Ohio border. Michigan roads/dirvers were fairly qwik as well. All 3 states had WAY better roads than IL.

[Guest wally888]

Had an 89 that averaged 32 mpg at 65 mph-about 28 at 75mph.

91, had 2, has always been about 20 mpg, mix of hy. and city. Gets about 20 at 79 mph on trips. Never seen 22 mpg!

90 ragtop gets better mpg than 91 coupe.

Cars, had 5, are very speed sensitive. 91's, had 2, get much less mpg than others, had 3, or so it seems.

Other than replacing plugs, wires, oxy. sensor, pcv valve, using injector cleaner, what else can one do (forget going slower) to increase mpg?

[padgett]

Really the only thing left that would help at Interstate speeds is taller/narrower tires - something like 205x75x15s but might look a bit odd.

One parameter often overlooked is tire inflation. On a 100 mile trip to St.Augustine with 28 psi my average (including some towning) was 24 mpg. Raising the inflation to 35 psi for the return gave 27 mpg.

Now this is a little lower than actual since I have 225x60x16 tires that give about a 5% speedo error (reads low).

Also I find that the mpg is maximum between 47 and 62 mph (appropriate since the 55 mph national speed limit was in effect) and drops as speeds increase.

And finally best mpg is with the windows up, headlamps and sunroof down, and a/c off (in other words at 30-60 degrees F in daytime).

Around town is entirely different - speed limits 25-45, frequent traffic lights, traffic all drop milage so I see over 30 mpg at 47 (lockup) mph but average is more like 17-19.

So "your milage may vary"

[Hank Ryan]

For the 112,000 miles that I had my 1991 Coupe, I averaged 21.80 mpg. Tank averages ranged from 19.5 to 26.5. I almost always used 89 octane fuel.

[Guest F14CRAZY]

Hmmm...with the stock airbox, more air's available to the intake with the headlights up...could go a few ways.

My supercharged freeway mileage is within a couple mpg of stock. Considerably less in the city (understandable...) and when towing something.

[Guest DTerry]

hmmm. I did have the fronts down to 32 psi to correct for a little bit of tailwag that came with the new (inexpensive) tires. Sidewall flex. Rear still at 35. That could account for the difference, I suppose. Damped the tailwag, though.

[Guest imported_dantm4]

I usually average around 25, but on a recent trip to Nashville I got around 30 if you discount the few stoppages I encountered (was stuff on the hwy for about 1.5 hours at one point). The engine is pretty fuel effecient on the highway but uses a lot more fuel when stopping and going in city driving.

-Dan

90' Black/Tan Coupe

[Guest tomt]

Randy:

I'm right with you on 29 mpg on my 89. First day out, I was getting 30.5, but average of the entire Lansing trip with side trips included was 29.

Also to D. Terry. I wouldn't be too quick to think you have a low a/c problem because of the warning. It seems at this time of the year I always get a false warning and others here have as well I have seen an explanation but forget where. It always occurs when you first don't need it.

[Guest MauiWowee]

Yep, I got an alert late Sat. night, temp about 47 degrees. <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[Guest F14CRAZY]

As Maui said, the Reatta climate control turns the compressor on like ALL the time. Even when you surely don't need air conditioning. And with the climate control already blowing warm air. Because of this, in the fall and spring, I use ECON

[Guest busconv]

Picked up our 90 Convertible with 71,000 miles about 10 days ago and on the trip home, about 340 miles, got 29.2 with the wife driving it....about 60/65 average and the wife all smiles when we arrived. Think that pretty good, and more than expected. Going to keep track but will not be driving it very much...shows and the occasional sunday ride. Did take it for a 105 mile drive last Saturday and did enjoy every moment . Smooooothhh, yet perky when needed, solid as a rock. Was 95 degrees and the a/c was perfect. I have been following this site for a couple of months and now convinced that the enthusiam of all of you out there is catching. Hope we will enjoy our Reatta for a long-long time.

[DeeBee]

THat is the Reatta for you/ About a month ago, took an 1800 mile round trip (bought it to drive it) and got between 30 and 34. The 34 at 55 in Oregon.

I always get very high 20s and low 30s. Last trip to LA and back, 85mph and up it dip to 25 but my foot was in it real deep. Triple digits at times, after the strut change. Cruises at near triple digits real nice.

[wellsguy77]

when I drove my 89 from Tampa to Dallas, I averaged about 28mpg, and that was before I let my mechanic tune it up, fix the E041 code and a couple of other mechanical things. Now it runs and handles beautifuly, now I am ready for another road trip, maybe NY to visit my uncle. I hope I would be able to average 30+ mpg like some of you other guys.

[89REATTAJIM]

Yeah, look at the help you had changing your air filter, etc. Glad all is well.... <img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

[Guest maybe2fast]

3" cone intake, removed cat and 2.5" enlarged pipe with exhaust manifold restriction removed. GMTUNERS.com chip with egr turned off and advanced timing. and big heavy 17" wheels. I averaged 28-29 on a trip up North of about 400 miles I think. I was getting better mileage going up, I was in a hurry coming home. I think I could have squeezed 30mpg. Oh... 165,000 miles.

[Guest F14CRAZY]

BTW, Don, hold on to your Driftwood coupe. I believe it was the only color NOT represented at the Homecoming

[Guest EDBS0]

505 miles is my record on a tank at 8 to 10 over the speed limit.