Computer mpg readout

[lvuj7]

Does the computer readout for mpg and avg speed still read correctly if you put bigger tires on. 265/65/17 to 265/70/17. Does it automatically correct itself and figure it all out, or should I not rely on it. I know that they will slightly decrease, but i just wondered if the computer figures it out by itself

 

[majewski]

Did it ever read out correctly? I could drive mine on the freeway, downhill, with a tailwind, or on back roads uphill, pulling a boat with a headwind, and it would still read 18.6 mpg

 

[CJ3Flyr]

Does the computer readout for mpg and avg speed still read correctly if you put bigger tires on. 265/65/17 to 265/70/17. Does it automatically correct itself and figure it all out, or should I not rely on it. I know that they will slightly decrease, but i just wondered if the computer figures it out by itself

Somebody here said theirs actually became accurate after changing to 265/70's. The MPG readout is notoriously whacky.

majewski posted
Did it ever read out correctly? I could drive mine on the freeway, downhill, with a tailwind, or on back roads uphill, pulling a boat with a headwind, and it would still read 18.6 mpg

Do you ever reset it? Push and hold the reset while you're driving. I'm sure you have and you're just making your point.

The more data it has stored the less it flucuates over short windows of time.

:cheers:

 

[Mirlen]

Did it ever read out correctly? I could drive mine on the freeway, downhill, with a tailwind, or on back roads uphill, pulling a boat with a headwind, and it would still read 18.6 mpg

Crap, mine must be busted, it reads 18.3 *sigh*

 

[majewski]

Well that extra 0.3 mpg must be because the previous owner was a little old lady who only drove it to church and back on Sundays. ...at least that's what the entirely honest and trustworthy sales person told me when I bought it :lmao:

 

[lmlenzen]

You guys do realize that the MPG shown is an average from the last time that it was reset right? If I reset mine it will show 7mpg as I accelerate and then start to increase as I cruise.

 

[toto]

The trip computer is just plain not accurate, even if you keep resetting it. It's about 10% too optimistic.

I leave mine on Outside Temp.

 

[Uneek]

I leave mine on Outside Temp.

Same here. Nothing on the mileage computer is worthy while and more gimmick than anything else.

I think on the SR5 and SE, the Outside Temp display is permanently on, because on the Limiteds that location is used for the passenger side temp setting.

 

[lvuj7]

i guess the reason for my question is so that I don't run out of gas someday because it says that I have 20 miles left and am stuck on the highway somewhere wondering why the computer lied to me. is that part still reliable?

 

[DeNz]

i guess the reason for my question is so that I don't run out of gas someday because it says that I have 20 miles left and am stuck on the highway somewhere wondering why the computer lied to me. is that part still reliable?

I always do a long drive ( state to state travel ). Sometimes I use it as reference on how many more miles i can go. What I noticed was the meter was showing shorter distance but the gas can still go further. In this case I just follow what the meter reading says just to avoid running out of gas.

 

[teampwr2]

Dont forget you have 2 tripmeters and a low fuel light , you can always fill up and reset 1 trip meter and compare your actual mileage to what the on dash meter shows /

 

[majewski]

Trip Meters and Odometer

Yep, I use them all. The odometer, obviously, has the total vehicle miles. Since I bought it used, one trip meter was reset when I drove it off the lot and has not been reset since, and the other trip meter is reset every tank of gas.

For whatever reason, I decided to do that and also write the miles and mpg on the reciept every time I fill up and keep it in an envelope in the glove box. Once of these days I'll run an Access program to do trending etc.

The one useful thing I did get out of this anal-retentiveness is that I immediately noticed when the changeover happened between winter and summer blend gas. My MPG jumped 1.5 miles in mixed and 1 mpg in freeway.

...I need a hobby or another old house to rehab...this kind of behavior ain't right!!

 

[r32]

That entire center area of the console where the MPG readout is...I never even use the thing. Never look at it, except maybe the time. I was thinking of replacing that with something else, maybe go custom with some buttons or switches for stuff.

 

[ran]

I just 1000 miles on my /07 this weekend. The readout went from 19.1 to 19.7 over highway miles and coast line to 4200 elevation. I do not have final MPG but it is close to 21.


_____________
'07 SE Titanium V6 4x4

 

[t65k3]

If you want to get accurate readout, try to reset it before each different road conditions. Furthermore, more mileages give you more accurate results.

I reset mine when I get on highway for a long ride. With a average of 75-80 mph, I get > 22mpg, sometimes 23.1 mpg as the highest. I have a 03' V8 RWD.

If I leave it on for a while with mixed city and highway, I usually get ~18mpg. I tried to confirm the result by the distance between places, time, and amount of gas I put in. It's not 100% accurate but close.......

 

[drmorbius]

Does the computer readout for mpg and avg speed still read correctly if you put bigger tires on. 265/65/17 to 265/70/17. Does it automatically correct itself and figure it all out, or should I not rely on it. I know that they will slightly decrease, but i just wondered if the computer figures it out by itself

There was a thread quite a while ago in Audio and Electronics on this forum I think by Rando where he states that the MPG on this display is arrived at by monitoring the activities of the#1 fuel injector and a mod was generated by Iowa4Runner to make it more accurate..http://www.toyota-4runner.org/showthread.php?s=&threadid=5635

 

[seh750]

You guys do realize that the MPG shown is an average from the last time that it was reset right? If I reset mine it will show 7mpg as I accelerate and then start to increase as I cruise.

I actually got mine to max out at 99.9MPG yesterday by resetting it just as I crested a hill, then I coasted down with no gas.

If you really want to know your MPG over time you should use a spreadsheet or software package that keeps those statistics and get gallons used from pump receipts.

 

[charlier180]

If you really want to know your MPG over time you should use a spreadsheet or software package that keeps those statistics and get gallons used from pump receipts.

For me a spreadsheet is the most accurate way to measure MPG.
Over the nearly 4 years I have owned my 4Runner, I have found the dash mounted computer is anywhere from 12-20% higher than the calculated MPG from the spreadsheet.

This is why the dash mounted display will always be questionable for me in virtually any of the current generation 4Runners.

 

[Uneek]

:iagree: with charlier180. I keep mine on a spreadsheet. My spreadsheet keeps track of the mileage on each tank plus a running average, best and wosrt mileage. Very simple formulas. If anyone likes, PM me your email address and I'll send the blank Excel sheet over.

 

[t65k3]

In addition to this.....

I noticed that, for example, when you are driving 75mph with 2400rpm, you hit a bit more gas and you have a speed of 78mph but 2200rpm (to the next gear). You get better gas mileage. Higher speed and more fuel efficient.......