Speedy Mike

Nope.

ASSUMING you are not in arctic conditions, you WILL get BETTER mileage, UNLESS you cant keep your foot off the gas due to the INCREASE in power..

97twd

We are talking about 5 to 23 degrees. IT does get colder but that is the norm. So we are saying that the truck is burning cleaner and any thoughs what might be wrong in the summer time??? What should I check?

Thanks for all the input.

shotgun

Mike, did you read any of the links I posted?

I don't disagree that colder air is denser air (physics again). Of course, denser air also means more wind resistance. Right?

These engines have an optimal operating temperature. Even if fuel flow and air flow were equal to 70 degrees F, when it's 10 degrees F, the engine cannot use the energy in the fuel as efficiently. Ever watch NASCAR? Ever hear the crew chiefs talk about putting more tape on the grill to get the operating temperature up in the 220-230 range? All lubricants and liquids (oil, transmisison, cooling, etc.) have a higher viscosity at lower temps. Higher viscosity requires more energy to move.

Drivers use the heater, the defroster, windshield wipers, electric seat warmers. The extra demand on the alternator creates additional drag on the engine.

Then there are the winter fuel additives (which burn less efficiently).

Clearly 250 articles and posts can't be wrong...

Speedy Mike

AGAIN Shotgun, you are talking about arctic conditions. Im talking about a cool day in FL. His profile and initial post says nothing of location or what cold air implied. And you are repeating everything I just posted in the last reply on page 1.

I'd clean the maf sensor with non residue electronics cleaner, change the air filter, remove the tb and clean behind it, check codes if you have any, check and replace vacuum lines that are dry rotted, check and replace spark plugs if you have more than 50k miles on them, change plug wires. In order of priority that's what I would do. A basic tune up.

If you have any codes, or rough idle, then you may have another issue. If you have p0401, it most likely is the DPFE sensor for the egr.

Could possibly the o2 sensors damaged from water/ice, but at $45bucks each, thats the last thing i would replace

blackyFX4

both sides are bringing up good points. not sure why there had to be name calling, but whatever. lol. i always wondered about the black in the tips too, so this has been a helpful thread. thanks

scubasimmons

I'm assuming the quote regarding summer mix gasoline freezing at 45 degrees is a typo.

It absolutely doesn't. I'm not actually sure that there is a temperature on the planet where gas actually freezes. I do believe it's abiity to burn is severely hindered at -100F.

Speedy Mike

my mistake on the freezing point of gasoline, it's that diesel begins to jell around 32*.. that quote was from another forum..

fido083

dont know if anyone mentioned fuel temp. warmer fuel vaprizes faster. winter formulas may help this but warmer is better to a point. Faster vaporization, richer mix, comp leans out = better milage. I live in Cincinnati and notice a 2 mpg difference between summer and winter. Summer being better.

BigRedXlt

Mike, shotgun is right. 97twd was asking about temperatures between 5-23 degrees, while this is not arctic temperatures we are not talking about a cool floridian day. Engines function less efficiently at lower temperates causing lowered gas mileage for short trips because the engine does not get time to heat up to optimal working temp.

I was also reading earlier on this forum that the torque converter clutch does not kick in until the transmission has reached a certain temperature I want to say it was somewhere between 120-140 degrees. Once again if the person is not driving a long distance just short trips this would be another reason why mpgs drop in the winter.

Also my mpgs drop significantly in the winter.