Hi,
I have been getting prety bad gas mileage as of late. Anywhere from 12-15 mpg. I dont adsactly drive it nice but I should be getting better then this as I have gotten 20 arround the city and 24-26 on the freeway in the past.
Just would like recommendations on what I should check. Air filter was a reusable and had that cleaned and oiled up 10k miles ago. Injectors? I really dont know where to start.

Thanks,
Andy

 

fuel filter, o2 sensors, plugs and wires, pcm tune, tire balancing and rotation, maybe clean your injectors or just use lucas fuel injector cleaner to your gas. check to see if the cars throwing codes, change all fluids, check bushings, suspension parts.
Thats about all i can think of at the moment.

 

Try cleaning the MAF sensor too. I've seen (and experienced) many cases when the oil from the air filter contaminates the MAF. This gives an inaccurate reading, thus providing poor fuel economy. I used brake cleaner to clean mine, but many will say you must use the MAF cleaner.

 

Fuel filter, Plugs, are both new recently. I think I will throw a bottle of injector cleaner in the tank and clean the maf as also stated. Ive heard it is very sensative so i think i will use the maf cleaner. where can I get that? at the local parts store?

 

It won't hurt to make sure all of your tire pressures are good. You're probably going to be burning more fuel as well since it is much colder out.

 

Just checked them and they were all good. at 35-40 psi

 

usually in the winter you get better mpg's because the air is so much denser. I get about 2 more mpg's in winter than summer.

 

Letting the car warm up in the winter can cause a noticeable decrease in gas mileage.

 

I had that same problem too. It ended up my opti went was going out. I just had it replaced though.

 

Does your car start hard, take longer to start. If so you may have a bad fuel regulator and it is dumping fuel into your engine. Remove the vacuum line to the fuel regulator, if fuel comes out it is bad. Also check your fuel pressure. Lastly a injector may be leaking. You have done the basics, now you need to start checking the not so basic things.

HTH

andy schuck

 

How is the car running, good? You might also want to look over for any vacuum leaks.

 

Best thing to do would be a data log of the engine under a wide variety of operating conditions. A false lean condition would easilly cause a serious loss in fuel mileage, since the PCM would be adding fuel the engine doesn't really need. Faulty O2's, exhaust leaks before the O2 sensors or misfires can cause that condition. It shows up as elevated long term fuel corrections (BLM's).

Long drawn out cold starts and the resulting cold start enrichment use more fuel in cold weather. In the winter, many states mandate the addition of oxygenates to the fuel, which further reduces fuel mileage. I've don't recall an EFI car or truck I've owned in the last 20 years that got better mileage in the winter.