I bought my car new with 10miles. My fisrt fill up i got 31 my second was 29 and this last one was 30. I take the miles driven divided by gallons put in=MPG. I have a manual its a mix of city and highway.

 

umm just a thought that some of you guys are missing.

the wheel size is really important as well. Not just because of weight (though that is definately a factor). I assume you are taking your odometer readings as they are and not adjusting them for any calibration issues?

For example my new tires/rims were about 1.1 x the size of the old ones. Since I never did any recalibrating, there's a disparity between the amount of miles I travelled on the odometer and the ACTUAL amount of miles travelled.

Redo the math comparing your tire size against the OEM tire size.
its should be something like:

(R + 2 * (T * S/100)) / (15" [convert to mm] + 2 * 185 * .6)

R is the rim diameter in mm
T is the tire width
S is the sidewall percentage

Assuming your wheels are bigger than stock, it should account for some of the difference.

Assuming a 10% larger tire size, you are looking at 23-24 mpg.
Which depending on driving style and the heavier wheels is a bit more conceivable.

 

Actually, my odometer was 3% short with the stock wheels/tires and is 6% short with my new wheels/tires. In my milage records I track not only the 'raw readings' but the 'corrected readings' so that I have a bit more accuracy. (I get, of course, a wide variation in MPG depending on what I'm doing/how I'm driving. Relaxed freeway cruising, over 36MPG, drive-it-like-I-stole-it in the city and I drop to very low 20's.)

Just as an example is is a portion of my milage records:



Tom

 

wow tom... we should have a tom appreciation day.. you have answered almost every question on these forums.

 

So I filled up again today and taking everyones advice into consideration, here are my findings:

OEM tire size: 195/60-15 = diam. 24.213 or circum. 76.066

TRD wheels/tires: 215/35-18 = diam. 23.925 or circum. 75.163

This equates to a difference of ~ 1%

Unless my math is wrong, my indicated 221 miles traveled equates to an actual 223.65 miles. Took 10.4 gallons to fill up which equals: 21.5 mpg!! Granted I haven't factored in wheel weight (not sure what the TRD wheel/tire package weighs) but I doubt it's much different that the stockers 37 lbs. If I'm wrong in my math here, someone please correct me before I start making phone calls. Sorry to keep such a boring thread alive, but I'm really diassapointed.

 

OEM is 185/60R15, and with the OEM tire/wheel setup the odometer is commonly off by 3%, showing 3% FEWER miles traveled.

The only way to KNOW the actual milage correction needed for accurate calculations is to calibrate the odometer milage shown against something external - for example 30 or 40 miles of mile-markers along a straight stretch of highway...

Good luck!

 

For the first 5000 miles I have been getting a consistent 33mpg. Mostly use it to commute to work - 7 miles suburban streets, 13 miles Interstate highway @75mph. Auto transmission.

 

EDIT: Forgot to mention that mine is BONE STOCK.../EDIT
2005 5 speed.... I got it in August of 2004, with ONE mile on it. My first few tanks were around 28-30 MPG, I was VERY pleased compared to the 13-14 mpg of my '86 Grand Prix...

I started again keeping track of my MPG on June 4th.... I fill up ONLY on Sunday's now, as it's my only day off, and allows me to see how far I can get on one tank....

6/4 - 9.463 gallons purchased - 311.9 shown on Trip-ometer - 32.959 MPG
6/11 - 8.888 gallons purchased - 315.4 shown on Trip-ometer - 35.486 MPG

The week of 6/4 - 6/11 I drove with MUCH less acceleration, (instead of shifting at 5000 - 5500, I now shift between 3000 - 4000....). I don't rev the engine at stop lights, or do the creep forward & roll back thing, and I don't down shift...


If you are getting UNDER 250 miles on 1 TANK of gas, there is something very wrong. Perhaps the car needs a tune up (but you said they already checked it). Perhaps you went to a gas station that had bad gas. I remember reading an article about 2 years ago (just before getting my xB) that was about gas stations in Southern Cali that had gas with a high Phosphorus (sp?) content, which lowered MPG, and even cause fuel gauges to stop responding... I remember it, cause I read it shortly after my Grand Prix's gas gauge broke, but there was no report of bad gas around here..

 

I believe that was sulphur rather than phosphorus, and some cheap gas blends are STILL too high in sulphur - though not quite enough to kill most fuel senders. Just saw an article about that again recently.

(Of course in Cali it could have been phosphorus - Cali always tends to be, uh, "unique.")

 

Here is a link to a thread I started late last year.

https://www.scionlife.com/forums/vie...914&highlight=

I know it is long (7 pages), but there are alot of questions asked and answered in there. Please take the time to read through it. It may help you.

As of right now, I stopped stressing over it. It does get crappy mileage in town 'putting' around, but I have figured out that once we get on the highway for a tank or two ( we travel a lot), it goes back up to 35-38. And that is fully loaded!

My dealer NEVER looked under the hood after three visits. They said it was 'the gas in the area'...BS, but what are ya gonna do?

HEre is what I would do...On your next day off, fill it up and drive on the freeway till the fuel light comes on. When it does, fill up and figure the mileage. Drive home, fill up and figure the mileage again. I was surprised to see my xB go from a measely 21 MPG to a whopping 38+ in the course of a few tanks (on highway, from CA to LA AND fully loaded with 2 people)!

 

Lol.... my bad.... it has been a loooooong day here at work... I still have an hour to go.... Anyways... it WAS sulphur.... not phosphorus....

 

One further thing to consider is that Toyota strongly recommends "Top Tier Gasoline" ONLY be used in their vehicles...

http://www.toptiergas.com/index.html

 

I think I'm going to make an appointment to go in next week...I don't care how you look at it, when the gas light comes on at around 195 miles, somethin' ain't right! BTW, I do use "top tier" gas (i.e. Mobil or Chevron usually).

 

Get that sucker checked out right and don't let them blow it off on some lame excuse like it's the way you drive. Even while spending the day at the drags my MPG were still in the 27-28 range. It sounds like a stuck or leaky injector or a bad O2 sensor.

 

Thanks for the comments and support guys! I look forward to meeting some of you SoCal guys in the near future!

 

Good luck with the dealership. I am not saying they won't look at it, but the one I took mine to said that the ECU is "so advanced, that if there were ANYTHING wrong, it would throw a 'check engine' light". After the third time of hearing this, I gave up. I was POed over 21-23 MPG we were getting for months. If you read through the link I posted, you may get some answers or ideas to try. Mine is fine after I take it on the freeway and run a tank through it at 65-70. The MPG goes WAY up. But it still doesn't explain the 21 MPG around town. There are so many factors that come into play, that I was trying everything I could and finally just gave up.

Good luck with it and PLEASE let us know what the dealer said because I am dealing with this problem too.

On a side note, I DID calculate my mileage with the ODO and my GPS at each tank. The GPS was giving me well over 50 miles more per tank (the ODO is off that much on mine). I would fill up when the fuel light came on (lets say 215 miles) but the GPS was telling me I went 280. I just used these numbers for reference because I can't get the actual numbers at this moment, but you get my point.

 

your odometer must be way off

 

The odo error you are claiming is an order of magnitude worse than mine was stock...

 

My odometer is off .5 miles for every 10 miles driven. Those numbers I threw up there in my last post were just for a reference. So technically, 5 miles per 100 miles driven give or take a few ( my ODO says 95 but my GPS says 100). As reported in the other thread, my tires are 1/2" taller than stock size. That added to the speedo beng off from the factory, it changes it quite a bit. I was told by several tire shops and the dealership to stay within 1/2" of stock size, either bigger or smaller.

I also would like correct my last post by saying that I DIDN't get a 50+ mile difference between my ODO and GPS...it was just a number I threw up there because my receipts are in the car and not in front of me. I will try to be more accurate in the future. Sorry for the startling numbers! LOL.

I will get the receipts and post REAL numbers later. Sorry for the confusion, guys.

 

During the "break in " period , i averaged 33mpg, now w/ 2000+ miles its 35+ 70% highway 30 % city driving. Mine is a 2006 5-speed.. :