wow, picked up 2mpg out of nowhere
 

just filled up the Cavy tonight, 11.554gallons, 335.9 miles 29.08 MPG!!!

the car normally averages low to mid 27s with 26s when i goof around

i didn't do anything special, or different then usual, that i know of, tracey thinks it may be because we didn't use the heat as much this time...i don't see how that can make a huge improvement, we don't usually use it a whole lot anyways to begin with

the only thing that makes sense to me, is possibly the computer learned the additional airflow from the ram-air & K&N filter...possibly

Well, FE economy is just one of those things. I mean, look at my fuel log, it can be all over. Perhaps you're just more unconscious of ecodriving, :)

i dunno man, all i know is that i hope it continues this 29mpg streak ;)

I don't know if this has anything to do with it, but in Maryland it has been raining a bit recently. I have noticed a slight gain in mileage while it is raining compared to when it is dry.

You'll know on the next tank. ;)

the only part of useing the heat that would affect your gas mileage is the blower fan, a vehicles heat comes from waste heat from the engine, and that is "free" altho running the blower fan puts an electrical load on the engine, not a great big one, but enough of a load that it can affect engine idle speed.

Until the engine is fully warmed up, running the heat will hurt your mileage. Cold engine = less mpg. Running the heater will slow the warming process, so more time is spent with the engine cold. Even having the temp set to heat, without any fan, will take some heat from the cooling system.

"Even having the temp set to heat, without any fan, will take some heat from the cooling system."

I've been told it's not enough to matter. There will be a small amount of heat exchange but I'd wager it's peanuts, unless maybe in something like a Metro 3-banger that has a hard time heating up anyway.

I'd have to agree with you both. During warm up, I think its beneficial to not run heat to get the fastest warm up. However, once it is warmed up I see no problem with blasting as much heat into the cabin as you want. I don't think you'll see much of a decrease in effeciency as the engine is already producing tons of excess heat.

... or a 4-banger civic with aluminum block. With a complete grille block and the heater temp set to Cold, it takes all of my 11-mile commute to get up to temperature. It's 10-20 degrees colder if I have it set to heat, even with the fan off. Fan on, even colder.

Once upon a time I looked into the issue and concluded that a person should really avoid using the heater blower until the engine is fairly warm, but that until then the position of the heater temp control didn't make enough difference to show up on the radar. That seems to be true on all of my cars.

malibuguy -

Oh, I meant to tell you. That's my two MPG. I left it on the counter at the diner the other day and haven't seen it since.

But, you can keep it if you can maintain it over the next few fill-ups. Keep track of the weather and try to see if something changes. Also keep track of the MPG "bad times" so you know whether or not your subsequent fill-ups are biased against this one.

CarloSW2

Absolutely it matters. The engine sucks fuel much faster when warming up, due to the richer mixture. Putting heat thru the heat exchanger will make the warmup take longer because that heat's not going to the block to warm it. So your mpg will be less than optimum the whole extra time it takes to achieve warmup. Regardless of what you do with the fan.

Lots of stuff matters now - stuff that didn't matter back when gas was $0.75 or $0.35/gallon. I can remember those days!

IF the heat exchanger is not EXCHANGING HEAT via little-to-none airflow the heat loss is also MINIMAL-TO-NONE.

Well OK.
Someone could test this with a Scangauge - or we could just let it go and figure that drivers will turn heat on or not, according to their best judgment.

Frank, are you ready to start a gaslog? Or post your ride in the garage so we can see what you're driving?

i know that, what i was reffering to was the electrical load from the blower fan, which is why i feel that can't be right cuz, its not that much

anyways, Traceys been doing alot of running around driving on this tank, she does do the neutral costing, but thats about it, we will see what happens, plus, it'll show how she is doing, normally i'm the one driving her car

I notice that my engine runs about 10-20 degrees cooler with the heater on... Depending on how high the heater is turned on. They do say when your engine coolant has overheated to turn the heat on high and to the floor. open the windows etc. The coolant is where you taking the heat from, if they could harness the extra heat that's just ambient in the engine bay, then that would be even better since the coolant is actually doing something.

i'm actully planning to remove my HVAC in my one malibu & replace it with an aluminum panel...i yanked the a/c out years ago, but i'm somewhat hesistant to lose heat...but i thought, the old corvairs used to grab heat off the exhaust...why can't i?? even tho i get tons of heat from the floor

so maybe i might try to set up a little fan & ducting on the headers for some heat if i'm that desperate, but its a race car & i barely drive it, so its not like life or death

well, last tank...26.35mpg...way low, but not bad considering the driving on this tank, still above factory #s

Stupid K&N dang expensive piece of plastic garbage, because of their in-your-face marketing tactics it took more than a few months to find the OEM one for my antique car!

Everywhere I looked K&N's plastered theirs in my face and I couldn't get around it just to find the normal one, but if K&N thinks I'm sticking their mod on an original antique they are dreaming for sure.

Washable filters, in what, cold water?
How is cold water going to get rid of road grime?
If dust was the worst that got on a filter we could just shake the paper ones clean.
And just how safe is it to throw the K&N thing in either the dish or the clothes washer, is it all right to do that? Because by the time I hand wash it with warm soapy water I could've just got a $5 paper one and been done with it.

So since I buy all my cars used the first thing I'll be sure to do is look under the hood, make sure it's got an OEM filter, and if it doesn't I RUN!

WTF, you have to use a cleaner to clean a K&N, it basically degreases it, you can't just plain rinse it

paper filters load up very fast with dust & start dropping flow right away, while the K&Ns don't get affected, it holds onto the dust & still flows better then paper

thats the main reason i run K&Ns, i don't have to worry about them at every oil change, i check 'em every 20,000 or so

K&N's dont filtrait worth a crap tho, reguardless of maitenance..
I'd rather run a AMSoil foam filter, but they dont have a direct fitment for my vehicle. :(

I've read that a few times. It's possible - low ambient pressure, warm temps + high humidity = slightly reduced aero drag, for one thing. But it would be a small effect.

PS - welcome to the forum.

I run K&N. YES, YOU HAVE TO USE THE CLEANER STUFF BECAUSE IT DECREASES IT, THEN YOU RE OIL IT!!!

Yes, K&N's filter considerably less, But My thought about them is, I'm not filling the land fills. We're getting more and more people everyday, and the world's land is getting smaller and smaller. we can't just keep using up land for trash. Oil supply is probably more important now, but sooner or later, it's gonna be like that situation, only with amount of land.

Oh, and for the rain thing, baseball players like it when it rains, cause they can hit it farther from the low pressure, yet higher temps. Less drag on the ball and just a few more feet equals over the fence or not.

For an SUV, this = GOOD, just like a car that gets 10 that gets 10 mpg more than normal, that's an 100 percent increase, but a car that gets 100mpg gets 10more mpg = only like 10 percent increase.