Well, I've read a number of the MPG type forums and gotten some great information. Sounds like I need to slow down, above all, but I was not so certain about the effect of the windows on my driving. Here are my stats, from Personal Vehicle Manager, an app on my Cingular PDA:

Average Fuel Economy: 28.25 MPG
Most Recent: 28.94 (Exxon) note that all MD fuel is E85 which I've heard is less powerful
Average Price: $2.54 (including initial free tank)
Distance: 1,671 m
Total Fuel Consumed: 55.16 Gal.
Total Fuel Cost: $198.59
Thats 3.54 Gal / 100 miles

So as you can see, I've been a bit frustrated with my mileage. I have a '06 Auto. I personally tend to not use the A/C whatsoever, even at 80 on the highway, but now I think I should, and go like 65. Since it has been 100+ around MD lately, I've used it on streets and roads as well, is this detrimental?

Focus your poll answer on the topic of the current heat wave, and summer weather in general. You can reply with your MPG if you want but there is another tread for that...

note that all MD fuel is E85 which I've heard is less powerful

Incorrect. E85 will corrode the plastic/ rubber parts in our vehicles. You are probably talking about E10.

I roll with A/C on when I am hot, and my use of downed windows does not reflect the A/C's running. This means I do roll with the windows down and A/C on when I feel like it. I don't really care about saving one mpg to feel comfy.

Highway driving is always windows up.

E85 is NOT approved by Toyota/Scion in our vehicles.

Just did about 1400 miles cross-country, across a couple mountain ranges, most of it in 90-98 temps (talking Western mountains, not Eastern hills).

Except for one hill I have past 'experience' on (cooked a Jeep - continuous climb with roughly a 2000 foot elevation change in just under 10 miles - Vantage Hill, I-90 Vantage to Ryegrass) I had the A/C on at all times. Didn't help my MPG much (neither did buzzing along in the 75-95MPH range for most of it), but definately helped my 'temper.' I'm NOT good in hot weather. :(

Mostly pulled in the neighborhood of 30MPG.

Interior was nice and comfy, even in full sunlight - another plus for white cars... :)

One more thing... I got my front side windows tinted 20% and a matching strip at the top of the windshield. This cut heat dramatically.

Also, sound deadening is a great insulator.

I guess I'm a trooper (I don't know if my opinion counts seeing as I don't own a Scion yet) but I drive in the Texas heat and I never use my A/C unless it's 100+ and then I'll cool down my car for a couple miles until it doesn't burn my hands to touch any of the interior. Other than that I never use the A/C. IMO it wastes gas. As much driving as I do I don't like paying $35 plus a week to fill up my car. Slowing down will help. Hauling @$$ at stop lights burns 33% more gas than gradually getting up to speed.

watch mythbusters. They prove A/C gives better gas milage.

watch mythbusters. They prove A/C gives better gas milage.

I actually saw that episode but in my car I swear it doesn't.

sidenote: they found out the fastest way to get beer cold was ice, water and salt. 5 minutes to get an ice cold beer. 8)

I know this isnt a Scion comment but our mechanic told us that our 1979 Lincoln's A/C compressor uses 30 hp. That car doesn't have too much power to begin with, so I think it really depends on the car if mileage is affected.

Heh... The A/C compressor in my old '69 Chrysler was almost as large as the engine in my xB... May even have had a similar displacement. :P

The compressors in the xA/xB models are highly efficient and quite tiny. We don'thave all that much power to waste, so I doubt if they pull much power even with the swashplate at full tilt (there is no clutch on our A/C compressor - the compressor shaft ALWAYS turns when the engine is running).

Most modern A/C compressors are much more efficient than the older models, and the odd little electricly-variable-compression units like ours are specifically designed for low powered engines.

watch mythbusters. They prove A/C gives better gas milage.

yes! it's called wind drag.

a/c full tilt, and i seem to get better mileage on any of my vehicles with the windows up and the a/c on, vs windows down. when you have air pounding on your rear glass thru the windows, its just more friction to slow you down.

TallGuy - A/C affects your gas mileage... but not enough to notice.

Best tings to do... Slow down. Run A/C on highways instead of Rolling down the Windows... the wind resestance is a big factor... not in town tho... then it doesn't matter either way.

Another thing you might want to consider... your car is still new. Alot of times you have to break your engine in before you start getting the sticker-marked MPG.

Yes rolling highway speeds with the windows down is like driving a boxxy wind sock. The air comes in through the windows and drags the car down. Not to mention I can't stand the pounding pressure sounds I get with the 2 rear windows down. Talk about annoying.

watch mythbusters. They prove A/C gives better gas milage.

I was just going to say that. I knew it before the Myth Busters.... don't know from where though.

I *heart* AC.

i try to keep my windows down when it's not miserable out, i like fresh air...but this weather is too hot to not use the air

I drive with all 4 windows down in Phoenix unless I have passengers, 80 mph on the freeway when traffic permits. For the first few months my wife drove the xB for her 1.5-mile commute with A/C on all the time and got a lot less than the 30 mpg I'm getting now.

watch mythbusters. They prove A/C gives better gas milage.

I actually saw that episode but in my car I swear it doesn't.

sidenote: they found out the fastest way to get beer cold was ice, water and salt. 5 minutes to get an ice cold beer. 8)

works great, but keg-cicles suck. I found out 20 years ago that the best way to thaw a keg is a hot shower.

If you're going to be driving over 55mph constantly (that is highway driving), roll your windows up and turn your A/C on. Your mpg will go up, not down.

You could try that solar window fan that they sell on tv. I'm sure its a piece of ____ake - but you never know :eyebrow:

I've been doing an experienment with this to find out for sure whether or not my car gets better gas mileage with A/C. Right now it's looking like its gonna get right around the same.

I drive with all 4 windows down in Phoenix unless I have passengers, 80 mph on the freeway when traffic permits.

your crazy bro

i always have the ac on windows up and im averaging about thirty except the time i drove to tucson and got 35 with the ac on