Hi guys, recently for some odd reason, my MPG has dropped from 26 to about 22. I dont know if it's the colder weather or something else. My car has been pulling to the right slightly recently. Maybe that could explain teh increased fuel consumption?? I dont think it's my driving behavior, cuz I tried to keep that constant and keep my mind on my gas pedal.

but the thing is that I believe the car seems to be experiencing increased resistance. I drive on this highway everyday and it has this steep hill that strecthes about 1 mile. When I was getting 26mpg, i can just cruise(foot off the pedal) through the hill with no significant decrease in speed. however, recently that hasn't been happening at all. I am currently getting 15mph drop if i just cruise through it. I checked my tire pressure and it's the same as when I was doing 26MPG.

Anyone can shed some light on this issue?? oh and i have been using premium gas consistantly. Tires is still good, only had about 6500 miles on the car.

 

Tire pressure has a big affect on mileage.

Koz

 

Colder weather. Every car experiences it, because the engine works harder to maintain a constant temperature. Also, keep in mind that the maps used by the engine change with weather conditions.

As for tire pressures, were you comparing hot to hot temps? Keep in mind tire temps can GREATLY vary depending on road conditions, weather, and most importantly, driving style.

All in all, I wouldn't worry about it. If by next year with the same conditions (temperature and humidity), you can't "cruise" over your hill, maybe I'd have some concern. But probably not. Enjoy the car, it's faster when it's colder out!

 

17.5 mpg.

thats what the dash tells me, no matter how easy i drive it.

i dont know what wrong.

 

Do they put ethanol in your gas for the winter? That and colder temperature in winter may contributes to lower mpg? Lead foot?

 

exactly the same for me. the very best i got was 20 on a long trip to vegas

 

It's strange to hear people say the colder weather makes mileage worse being that I've lived in Texas my whole live, hehe. I get significantly BETTER mileage in the winter because the AC never runs, and there's only small use of the heater.

As for your problem, that does sound strange... I guess like people have said, it's either your tire pressure or the weather, or a little bit of both.

Is this highway or combined mileage?

It's so very weird in my car. I can get 29-30 mpg on the highway, meanwhile getting 17-18 mpg in the city. That is a MASSIVE difference. (Although most of my city driving is the three miles between home and work, where the engine doesn't get much time to warm up).

 

Noticed that you're in MO, I believe that they mandate a change in fuel composition for winter and add ethanol. That alone will lower both your fuel mileage and your performance. As stated before, cold weather doesn't help either. During this last cold snap here (Northwestern Washington) I've seen my mileage go from 18 around town to 13.7 (05 RX 330), of course that includes moving along at the blistering pace of about 12 MPH through snow banks and rutted icy roads.

 

its hard to get good mpg when your car is so fast

i just put it in cruise control and enjoy the ride. i love the seats =D

does anybody know if the seat warmers use gas? or battery? .... i cant live w/o seat warmers! its just too darn cold in the morning and night

 

I took this picture because I could not believe my eyes. I have no explanation for it. OAT was 57 degrees F, tire pressures are as spec'ed on the sticker, I did change from Castrol (dealer supplied) 5w-30 to Mobil 1 5w-20 at 10k miles, and I am now at a little over 12k (yes, I drive a lot of highway miles). Also, my all time average has finally climbed up to 24.2. That gives you some idea how much I drive between 70 and 80 with the cruise control set. BTW, at one point during the drive, I actually saw 29.0, but I didn't get a clear pic of it. Best before this was 27.8. Oh, sorry for the lousy cell phone pic, but it's all I had available.

 

Keep in mind the oil companies reformulate the fuel for winter, typically you will get worse economy in the winter (than summer) because of the additives.

I usually average 26.7 (on the tank trip computer) with my routine 12 mile commute. I also have noticed with the last two tanks my MPG being 23.4. Our weather is San Diego isn't too dramatic, so I don't think this is a factor, just the winter fuel. The best economy was a trip to Vegas, 29.8 MPG averaging 85mph. I am sure it would’ve been higher if I drove slower, but who can in this car?

Try adding tire pressure if economy is a concern. I have 38PSI in mine. The downfall with higher PSI is you won't grip the road as well in cornering.

I also only put Chevron Premium in it and have 6300 miles.

 

how fast were you going ? i was goin bout 80~90 and got 26mpg

 

well, come to think of it, this all started to happen when I got lazy and just pulled into Sam's club and got a tank of Sam's club premium fuel. I hope it's not their gasoline. Ever since then, I have been filling up with half a tank or so. So, I haven't really completely emptied my Sam's club gas yet.

I just filled my tank up with my usual gasstation premium 120 miles ago. I guess i'll see how this tank goes.

btw, why exactly does colder weather increase fuel consumption? besides the talk about different additives in teh fuel during winter season.

 

California doesn't have summer/winter fuel changeover. We get the highly oxygenated winter fuel all year round here. I always get much better mileage when I leave California and get real gas. If you are in NorCal, you have to get East of Sparks, NV to get decent fuel. Not sure about Oregon, but I did notice significantly better mileage in the IS coming home from Oregon than I got driving to Oregon.