I'm gettin about 28mpg on the highway, and I hear a lot of people get 32. I'm at 36k miles on the stock plugs. Would you guys attribute this more to the plugs or the altitude? I live in Idaho...

Could be a number of factors.
Air filter
Tire pressure
Rim weight
Load of vehicle
Driving type
How are roads? Straight, windy, up and down?

As Dave pointed out there are several factors that will effect your milage. My own observations are this.....

Rim weight- This was the single biggest gain in my mileage. I went from the 7 spoke Scion alloy wheels at 22 lbs ea to Sportmax 501 15 x 8's w/ stock rubber. These weigh in at just over 13 lbs each. This got me almost an extra 25-30 miles per tank.

This same thread went on over at SL a year or so ago and someone had posted that they try to keep the RPM's under 3500. I tried this and it made a HUGE difference in milage. Along with that, keeping to 70 on the freeway and also lowering my shift points makes the difference of about 15 miles per tank.

Using your A/C will also effect your milage in the summer. I never turn mine on unless the temp gets near 100.

Wind will have a dramatic effect on milage, say for someone who lives in like the Banning pass in So Cal where the wind is always blowing, especially during Santa Ana season.

Fuel's are forumlated differently during the summer/winter months. Typically you'll see less milage per tank during the winter. This is a factor in what part of the country you live in. My mileage drops by about 20 miles/tank in the winter. Combined with this is letting your car warm up on cold days. For some reason these little 4 cylinders will really suck up the gas while idling for 15-20 minutes warming up.

Under inflated tires are a huge mileage robber. It takes a lot more power to overcome the added resistance to tires that are 10 lbs under. This is the first thing I check if I notice a sudden drop in mileage.
Of course there are a lot of variables at play here. I set my bench mark by making sure everything was where it needed to be (plugs, air filter and such) Drove through 3 tanks of gas keeping the same conservative driving style. What I came up with on my car was this.

At 3/4 of a tank I had driven 100-110 miles
1/2 tank - 200 miles
1/4 tank - 325 miles
pushing it till the fuel light comes on 350.
This seems to be a constant for my vehicle in the summer. In the winter the mileage drops off too 325 @ fuel light.
I reset my "A" odo every fill up and check the miles driven against the gas gauge constantly to make sure that nothing drastic is changing.

If I drive like I normally do, shift at 4 grand, 80 on the freeway, and generally hauling ass, I can expect to get typically about 300 miles a tank. If I take it easy I can get that to 350 right before the fuel light comes on.

This post was last modified: 03-03-2008 05:04 PM by Peej.

Peej always has the Good Info... thanks man!

Very nice read.

Me and my box are one

Don't let your wife know.

me and her box are one too

i just checked the trip and with the gas light on i only got 250 miles to a tank. i will be checking my tire pressure and things TODAY for sure!

i am getting WAY BAD gas milage right now... im averaging about 22-25 mpg... this is not cool. i will be either getting a new or cleaning my current air filter and changing plugs today... i really hope this helps...

also, what is the tire pressure supposed to be? the tire says do not exceed 44psi and the doorjamb says 29 i think. im running 215/45's i think.

Put in what the door jam says. All tires say a max pressure of 44lbs at a certain weight. The psi is different for every car.

Currently I'm running 34 front and 32 rear so I can wear the middle of the tire a little.

im getting about 250-280 a tank, i'll be changing my plugs and cleaning my air filter, im actually thinking about changing wheels espcially if my job is going to have me driving to irvine everyday

Get some light weight 15's Carlos...

yea i want too but don't know if i could justify it too my gurl so im thinking about putting on some 15's i had on my pos escort

Sell the big wheels to a noobie who is just getting into Scions and buy yourself some 15's...