My 1988 GL 1.8 SPFI has typically been getting about 32-36 mi/gal. During the latter half of this year I have had to do a lot of maintainence and repair on the car and now I'm getting around 27-28 mi/gal. The only thing I can think of that might be related is that I've put some fuel injector cleaner in the fuel tank. Are there other things that I might try/observer?
Justin
Did you put new tires on? My average mpg went down when I put new tires on my car.
snipped-for-privacy@gmail.com wrote:
I did. Interesting notion. Maybe I can even experiment with tire pressure too. I figured higher pressure would translate to a more elastic, from an energy conservation perspective, contact with the road, but perhaps this is the wrong parameter to optimize for.
Justin
Tires from different manufactures can have diameters different by several percent. Add to that you now have about 8/32 more tread could be your difference i.e. you are going farther per tire revolution and it is not reflected in your Speedo reading.
Hi,
In "today's" tire world, it seems there's more variation in fuel economy from tire to tire than 15-20 years ago. More tires are "performance" oriented, meaning softer compounds, more aggressive tread patterns, etc. It's not a perfect measure, but I've found an inverse relationship between fuel economy and the UTQG mileage figure: in other words, a tire rated as "Treadwear 200" usually turns in worse fuel economy than one rated as "Treadwear 500" kind of thing. There CAN be big differences in fuel economy based on those parameters, plus the larger diameter Ed mentioned, and the pressure issue.
For myself, I've generally found a slight increase in pressure (2-4 psi over the door sticker) would help fuel economy, and handling, w/o hurting the ride. Above that level, you've gotta experiment to find what works FOR YOU!
Also, you mentioned recent "work" on the engine. What all was involved? Can you rethink anything that can definitely relate to economy issues, like timing, new sensors, that kind of thing? Maybe even a significant change in driving patterns? (A friend became seriously worried about the mileage on her new Camry--she bought it just before she retired, and drove it 35-40 miles each way, pure freeway, while working. Now, since she's quit working, she never seems to go more than about five miles at a time and seldom sees the freeway. BIG change in economy!) You did mention injector cleaner: it may be your mileage drops while the cleaner's in there (or it may not--I've had cars that dropped off, others didn't change, one even improves when there's a can of cleaner in the tank!) and then comes back as the cleaner's burned up. It may also be, if it's been a long time since any kind of cleaner's been run through, that you'll need a second can.
And then there's always the issue of "winter gas" and poor mileage that comes up about this time of year...
Rick
I just got lucky and found a complete set of 4 new tires at the local self-serve discount junkyard.
And that is the material point. In my case I'm in constant need of watchfulness and sometimes retrenchment. "The vehicle is not a toy or a laboratory but ultimately just transportation."
Minor work on the AC, power steering, and engine water systems. I've replaced the air flow meter with one from the junkyard (the old one died), the oil pan gasket, and the entire secondary ignition system during the past year: plugs, cords, distributor cap, rotor, ignition coil.
It is reasonable to believe this is also a contribution.
Justin
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