Sac State

With the temp hovering around 27*, I have noticed my mpg to have dropped about 2mpg in the last few weeks(gotten colder).

Does cold weather induce worse gas mileage?

I burn 93 exclusively, should I switch to 89? Save your posts about all gas is the same, yada, yada, yada. I disagree.

My '02 pinged like a gypsy tamborine running 87 and 89. Since I have been running 93 in my '03, no ping has ever been noticed.

Vato Loco

This not might answer your question, but I get better acceleration and performance during the cold weather.

Sac State

Isn't that the purpose of a FIPK, to supply the engine with cooler air to ignite the fuel better?

I am baffled.

BT17R

Depending on where you live and the politics of your state, it could be the annual Winter fuel formula change. The EPA designates the air quality of states based on sample quality. Some states like mine (Oregon) get a "Good" rating so no change is required. Other states that get a less than "Good" rating are mandated to use the Winter formula with oxygenates and higher vapor pressure made of lighter hydrocarbons to cut emissions and aid cold starts. Most drivers report about a 10% fuel economy loss running Winter formula fuels regardless of octane rating.

Of course politics usually challenges common sense. Although Oregon has "Good" air quality year-round, with few dirty air days in the Portland Metro market (2-3 per year), our last governor issued a decree mandating oxygenated fuel year 'round. That effectively raised everyone's fuel costs by reducing economy, all in a transparent appeal to environmentally conscious but common-sense deprived voters. \rant off.

jacksonpt

are you running your heat now? if you run your heat constantly, that will lower your gas mileage a bit.

ugadawg95

why would running the heat decrease your gas mileage?

as for the colder air giving you better performance, yes it does because cold air ignites better, hence having an intercooler on a turbo to cool that hot exhaust air down before gettin burned

Sac State

I live in by God, Montgomery County, North by-goodness Carolina. Our solution to the EPA is to dilute our gas with 'mountin litin' at 190 proof.

I don't think our state government is smart enough to figure out reformulated fuel. I get my gas from the same place as Cooter, Bo and Cletus.

BT17R

That explains the dual exhaust!

jacksonpt

I dunno exactly, but it's got to have somethign to do with strain on the engine. I notice a slight decrease in mileage if I run the heat or A/C.

Sac State

Don't forget my Dixie air horn!

4x4Lamm

Running your heat puts the same ammount of strain on your engine as say, windshield wipers. A minute electrical draw ammounts to nill. The heat is produced year round by burning gas in your engine, thats what a radiator is for. In the winter, turning on your heat will just channel some of that heat into a through convection and a few fans blow it into the cab. AC does decrese gas milage due to its parasitic nature. Try running at a very smooth idle then turn on max AC. A 200-3000 rpm increse is what I get. that is not much however.

44Runner

ACKKKKK

cold air is more dense

turbo engines do not burn exhaust air they run exhaust through a turbine that runs an intake turbine that sucks in fresh air

turbines create turbulence and compression

both turbulence and compression generate heat

intercoolers are then used to lessen that heat

cubuff4runner

44Runner is right

Cold dense air contains more oxygen so you should feel an increase in power during the cold months, however when you start your engine it is so much colder than during the summer months your engine will idle at a higher RPM for longer.

Higher RPM's =worse gas milage

If you start you vehicle drive it a couple of miles turn it off let the engine get cold start it up again yata, yata, yata. Your going to be getting bad gas mileage, but once your engine is warm you should be burning more efficient, with the exception of ethenol & other addatives.

Victor

Even with oxygenated fuel I get better mileage in the winter - about 50 more miles per tank. I attribute that to the fact that I'm not running the A/C full blast like I have to in the summer time. Actually - we've only got below 70 F this last week so now I don't use the A/C at all. By the end of January the heat and wind will return and there goes the MPG out the window again.

EDGE

Saw something on the news that said after Jan 1st they are doing away with MTBE a fuel additive that has been found to contaminate the ground/ drinking water.

Im unsure if the MTBE is used year round or only during the winter months but they said the effects of them taking the MTBE out will increase gas prices .03-.80 cents more a gallon, thays like 15 bucks more to fill a tank.

Anyways my performance feels better in the cold months and I loose 1-3 mpg during the winter months

Same thing could be said for the performance during the Summer months, ever notice when you get a cold spell and it suddenly goes from 90 degrees to 50 or 60 degrees and it's raining, the pressure increases and the car feels faster more dense air the engine can suck in

Toyota Punk

As I understood it, the AC compressor was used when the heat is on as well, not just the AC. How are you able to adjust the temperature if you are just getting engine waste heat?

I always notice a drop in mileage during winter months also. I'm not sure if Ohio uses the oxygenated fuel, I'll have to check. I've dropped from high 18's to mid/high 16's in the last month as temps hover around 20 degrees here.

ugadawg95

Correct me if I am wrong but running the heat requires no generated power from the engine so why would your mpg decrease? unless you were using the heat in conjunction with the defrost mode which requires that the a/c compressor be engaged which will decrease the mpg or just using the heat with the a/c on. i have noticed that when i press the AUTO button on my 99 that the A/C comes on by default but I always turn it off as soon as that happens...just my $.02

ugadawg95

thanks for clearing that up...can you tell i have never had a turbo? oh well

4x4Lamm

Good job expungeating (did I spell that right?)on my last post Steve S. The defrost uses AC to get dry air, otherwise that temp is regulated by the ammount of heated air vs. the normal air that comes in through the coweling. I haven't noticed any drop in mpg and I keep tabs on it with my palm pilot down to a tenth of a mile. Nothing out of the ordinary. I don't know anything about special gas, I just see the sighn at the gas station thet says "flameable, no smoking" and figure that will work fine. I'd be interested to know what you findout though.

cubuff4runner

Your AC compressor only runs when you are using your AC or on most newer 4Runners automatically turn on the AC with the defrost. Your heater is simply a coil under your dash which antifreeze always runs through. Turning on your heater turns on the fan which blows air over the coil. Definately no engine power loss.