Rock-a-Lex

iTrader: (4)

Maybe someone can help me out. Last year around this time I was getting insanely bad gas mileage (as the weather started to get colder out). I cleaned my plugs, cleaned the TB, got a Fuel Injector service and cleaned my air filter. It got a little better but still bad (12-13mpg) and that's driving easy!!! As soon as the summertime came I was seeing as much as 16-17mpg (keep in mind A/C was also used quite a bit) and driving more agressive...what the hell is that? That is a HUGE difference! All throughout the spring and summer and up to just about 1-2 months ago I was getting about 145 miles by the time I was at the 1/2 tank mark and around 265 miles very close to "E". Now, my car is at 105 miles by the 1/2 tank mark. Is there/could there be a problem with my car with A/F readings? I mean this is literally costing me ~80 miles less per tank! Please help and let me know what you guys think!

RTIS250

iTrader: (9)

Typically when it gets colder, the fuel mixture is richened up. Colder denser air requires more fuel. Cars are also faster when its cold out Maybe we dont have as severe of winters out here in CA, but i never notice a different from summer to winter. I recently turned off my AC (used to run it all the time), and got 2mpg better, haha, because my compressor is starting to seize.

JeffTsai

iTrader: (1)

See if the shop can get you a leaner tune. I tune my car as lean as I can without the engine bogging down or detonating. I can usually get my air fuel ratio to about 16:1-17:1 under idle and cruising. Saves quite a big of gas when I'm just cruising. I actually get better gas mileage now than I did stock...only when I don't floor it lol. It does richen up when it detects load or boost on the engine.

Rock-a-Lex

iTrader: (4)

Thanks Jeff...This seems like something I need to do. BTW, do all cars automatically richen up upon load/boost or do you have a special computer in your car adjusting that?

UberNoob

maybe its during the winter times the oil companies do a special winter blend where there is more ethanol thus reducing mileage as well?

Rock-a-Lex

iTrader: (4)

I'm sure that it's part of it but I wouldn't think it effects 3-4 mpg! The temps here aren't even that cold yet...maybe 50-60 degrees. I'm so screwed when the 10's and 20's come rolling around...have to get to the bottom of this.

Billh2

Years ago cars had air cleaner ducting that took hot air from around the exhaust manifolds. Introducing heated air into the engine in the winter time went a long way towards fuel economy. Gas mileage was still less in the winter, but taking hot air off of the exhaust manifolds was a big improvement. Repairing the hot air system was a priority for the tune up shop I worked at back then. Cars that got 19MPG in summer, and 14 in winter without the heated air system picked up around 2MPG with this system working properly. When they got rid of the carburetor and went to fuel injection, they also got rid of the hot air ducting.

flipicanez

iTrader: (1)

This may be a long shot, but try lower octane fuel for the winter. I know it sounds crazy, but my mechanic may be right (from a time driving a regular gas car) He mentioned in that kind of temperature that the cylinder needs that immediate explosion to better run the engine, or something like that.

One tank of 87 wont hurt, the computer will compensate anyways. I too have been noticing a flux in my mileage now that we are in the 40's and it will get colder here in Chicago.