Am I the only one who doesn't know the answer to this? Why does my milaeage semd to drop when it gets cold here in Cleveland. Lately nights in the 20s and days int he 30s and my mileage is around 15 with even city and highway driving. It usually is around 18 overall. Any help greatly appreciated.

 

I know here in California they change the additives in the gas. I think its MTBE, or something like that, and ethanol. Ive heard/might have seen a report that showed it to lower your MPG. I will try and find what I did again tonight, if I have some time.

Garrett

 

Yes, even gasoline has "winter blends" and "regular blends" just as diesel trucks deal with.

Your mpg shouldn't drop more than .5-1mpg during the winter because of the gas itself. Your warm up period also does a doosey on gas mileage. I know my truck has to idle for 15 minutes to be "ready out of the gate" so to speak, completely willing to drive regularly, and even then I still have to wait for the gearbox to loosen itself up a bit.

 

1) gas change

2)warm up period

theoreticall,y with no warm up period,or using same warm up perid during summer, and no change in blends, your gas mileage and horsepower would increase in the winter due to a colder intake charge and less humidity so you have a drier charge that will mroe readily ignite....in theory.

you do know to add air to your tires in the winter right? and let the air out in the spring? (serious on this one, not like rotaing the air)

 

I'm with Jimmy on this one. The tire pressure drops dramatically in cold weather,and even the warm up period here in Alabama has affected my mileage,and it's not near as cold as where you are.

 

My mileage has dropped from 19.8 to about 18.5 mpg. I have a 2004 Heritage Super Cab, auto 3.55, 4.2. I live in MD and the temps have really dropped in the last week or two.

 

Just a thought:

MPG could suffer DUE to the colder air. With the colder air, more O2 is introduced to the fuel system, possibly creating a LEAN condition (more o2 than gasoline) which the computer would then try to compensate for by introducing more gasoline into the fuel mixture, removing the 'lean' condition. By using more gasoline to regulate the fule mixture, MPG would then seem to suffer.

On the other hand, your acceleration and pickup should be much improved, requiring less "gas-peddle" to keep things moving.

Comments, arguments?

 

Just a thought,

Colder air is denser due to the molecules being less "active" therefore your rig can't as easily "push" its way throught the colder air. ie. more drag.

 

MTBE, the additive in oxygenated gasoline, is the main culprit, along with longer operation in open loop, due to colder temperatures. The increased oxygen in the fuel caused by adding MTBE makes the engine computer see more O2 in he exhaust stream. This in turn causes the computer to add more fuel. Adding more fuel increases the oxygen content of the cylinder, and the viscious cycle continues. Why, you might ask? Because our illustrious leaders in Washington decided that older carbureted cars polluted too much in the winter, so they introduced a fuel that would clean them up. In the process, they made the other 95% of gasoline powered cars and trucks less efficient and run dirtier, in order to clean up the other 5%. Makes a whole lot of sense, right? Also, the time the engine spends below operating temperature is when it runs less efficiently, and this is where the majority of polution, as well as wasted fuel, comes from in our modern engines. Once warmed, our engines run extremely efficiently, but are as bad if not worse, than the carb'ed setupsin the first 90-180 seconds of operation. My 1996 with a 4.9L does that too. In the summer, I consistently get 18-20 MPG on the highway, but it drops off to about 15-17 in the winter. Also, as Jimmy suggested, check your tire pressures, as they can make a realy big difference.

 

Thanks for all the responses to the question. Your ideas make sense and I have a follow up question now. Would it help to put a piece of cardboard in front of the radiator as I see 18 wheelers do to reduce the flow of cold air to the engine, thereby helping it warm up a bit faster and become more efficient in winter?? Or would this reduce my air flow and cancel the benefits of my K and N filter? Thanks for any and all thoughts and ideas.

Tom

 

you can also over heat too

 

Make sure your thermostat is working correctly. your engine should warm up fast, then stay put at operating temperature. Use the factory thermostat rating (most cars and trucks are supposed o be 190-205 degrees) at least during the winter. Blocking the radiator shouldn't be neccessary if the thermostat is working correctly.