Bang for the Buck - MPG's

[jglawnyc]

Hi Reatta fans.  I've been tracking about-ish 11 miles per gallon on my last 3 fills, representing a vast majority of around-the-town city driving.  I have a '91 with 135k miles.  Is this normal?  What are you all getting?

[DAVES89]

"Vast majority of around town driving" could be sitting at lights and idling. I believe I get somewhere around 16 mpg but we are a little more "urban" here in Wisconsin.

I do remember when I bought my first Reatta from a gut in Florida, the average he got was about 14.5 if memory serves me. I remember thinking "Florida to Wisconsin, how many gallons will I have to buy"?

Things to consider;

Spark Plugs

Spark Plug Wires

Oxygen sensor [this is often overlooked and can make a difference]

[AZ Ron]

I was getting 15.6 on my 88 with 117,000 miles.  I changed out the Ignition Control Module and coil pack and picked up 5 mpg on a around town drive.  This was the Autozone  Magnavox style ICM and coil pack.

I had recently replaced plugs, wires, cam magnet, cam position sensor, oxygen sensor and crankshaft pulley.

My next move is to either rebuild or replace the fuel injectors to see if I can even do better.

I have seen several posts here stating that Reatta owners get upper 20s and even 30mpg.

[DAVES89]

On just highway driving you'll get 28-30 mpg but not in stop and go driving.

[2seater]

Driving style, a/c use and where it is driven has a huge effect on mileage. The O2 sensor usually makes a positive impact, especially if it has been running poorly which has a detrimental effect on the sensor. Stop and go is particularly hard on mileage as the Reatta is quite heavy, heavier than the equivalent LeSabre.

 

Clean injectors are certainly a plus, for multiple reasons. The stock Bosch '901's are a good design, with a director plate style spray pattern, but modern tech "may" make a difference. I would suggest the Bosch type 3 injector in the stock approx. 19#/hr rating. They do seem to idle more smoothly and the slimmer and lighter internals allow the injector to open more quickly, reducing dribbling. Just be sure to get ones with the EV1 style electrical connector and the upper grooves for the fuel rail retainer clip.

[Ronnie]

My driving is mostly on rural roads. Hardly any interstate driving and not a lot of city driving. I live in a really small town.  We only have 8 traffic lights. Most of them just flash yellow after 10:00 at night. LOL I haven't reset my mileage in I don't know when and the CRT is showing 20.2 mpg right now. If I check using the old method of fillup-drive-fillup, the mileage I get is usually about 2 mpg more. I've been told the '88 had a defect in the computer chip that made the mileage on the CRT read low. I'm happy with 22 the way I drive.

[rogold]

You also might have a bad knock sensor, or a good knock sensor retarding the timing because its senses a knock.

[droid5977]

I've got 175k on my 90' vert and have consistently gotten 20 to 22 mpg city and highway combined.

[Frogware]

I just filled mine up today and got 18mpg and that is mostly stop and go traffic. It has almost 180k on it. When I took it on a road trip to Colorado I was getting around 26 - 28mpg. So not bad on stock plugs and injectors, which I plan on replacing soon.

[kiwigram]

I recently bought a '90 and on a recent round trip from Beaumont, TX to Austin, TX, I averaged 17.3 mpg. I have replaced the O2, the entire ignition system, plugs, wires, coil pack, and ignition module. Also the Cat. Converter, and the crankshaft sensor. Around town I am getting somewhat less than 12 mpg and on a run, still at 17. Now the goofy part. Obviously, the car is running rich, but the computer is coming up with code EO44, which is (Lean exhaust indicated). So I still need to follow the trouble shooting and find out why. And I see, Retired Mechanic, getting 30. Makes me kinda envious.

[Ronnie]

Have you installed a new O2 sensor? If not I would install one. I consider it something that should be replaced at least at 50000 miles as routine maintenance.

[DAVES89]

Just got back from a round trip of 250 miles on the Red. Mostly highway at 55 to 75 MPH. Averaged 28.5 on the CRT.

Maybe the cam sensor has failed? Don't know if they throw a code on the 1990 or if it has much effect on mileage. I have a 1990 but so far gas mileage seems right. We don't drive it much.