MPG, Hand Calculations, and Odometer Woes...

It seems to me that a couple of things are apparent. Some are getting close to advertised MPG numbers but many are lower. I believe this to be caused by several factors.

1. The odometer with Stock Tires seems to be off (low).
2. The computer calculates the mileage even lower.

Several members including myself have tested the odometer on long stretches of open highway against both GPS and mile markers. The results seem to show that even with the stock tires the overall odometer is off by between 1-3 miles per hundred. (1%-3%). So this means that you are actually driving more miles and the computer does not see it. This is compounded if you add bigger tires.

Also, from my hand calculations I see between .5-1.5 MPG better than the computer tells me. My overall average on 1700 miles is 17.3 on the computer but hand calculated is just over 18.

I think both of these things are causing the MPG results of the 2016 to appear less than advertised. Anyone else notice these same things?

 

That's another odometer off observation. Toyota would be smart to fix this one as it will show lower than actual mileage and could affect sales as numbers will be low.

 

Yes. Odometer is off 2.5% vs. GPS for me. I keep track of both real calculations and what the computer shows for each tank.

Miles, calculated and corrected mpg, computer mpg

395.5 23.01 21.8

326.8 23.71 22.6

234.2 20.79 20.3

362.7 22.21 21.4

379.46 22.35 21.3

359.78 24.03 23

380.5 24.64 23.1

 

Not sure seems to be accurate to me going from my honda accord.. My trip to work is about 12-13 miles one way and I get like 20-21 mpg backroad driving. I got 18ish today cause I lead footed my way here. Not sure 18 inch wheels on the limited would make a big difference in mileage.

 

In a trip that short it is hard to tell. 2% of 12 miles is only .24 miles. If the drive is an exact 13 miles your odometer would show 12.74. To truly test this out you need to do at least a 50 mile highway test using GPS and mile markers as a control.

 

Mine is just over 2% off based on mile markers with stock 265/70R16's which is about the same as the 2012 Tacoma I had.

 

Calm down. Some care, some don't. Life will go on.

 

Just filled up again. On board computer tells me 17.4. Hand calculation tells me 18.5.

 

I too have found that the computer has been 1-1.5 mpg off shows 18.5 but actually get 20, I also found this to be true on my tundra, would show 14.5, and i would get 16-16.5. Guess its opposite from what people are use to with the computer being generous.

 

I don't think it is as simple as hand calculating based off of mile marker measurements at 65 mph or so. Unless you always drive 65... the error should be speed dependent. Which means your hand calculation are off as well...

 

Miles travelled divided by fuel used is your mpg. Not much room for error. However I will give you the benefit of the doubt and do a test at a lower speed and see if it is the same amount off. It should be as the tires are the same size.

 

I'm 6% off. I would be happy with 1 to 3

 

I'm actually glad to hear the computer mpg is under-calculated. I had an Audi A4 that said I was getting 27mpg when I was actually getting 24mpg. I'm currently driving a Hyundai Sonata while I wait for my Taco to be built and the Sonata says I'm getting 31mpg while I'm actually getting 29mpg. I think knowing that you are at least getting what the computer says or better is better. It just seemed pointless the other way around and disappointing when you filled up.

 

WTF are you talking about? The odometer doesn't have any reference for speed. I don't think an of use are driving fast enough to expand the outside diameter of our tires. And why are your bringing mile markers at 65mph up?

 

I thought the way odometers worked in general translating rotations to miles was nonlinear and errors would increase depending on what speed you were at when it was off. LOL I wasn't say his tires were growing. Anyway, it's been a long time since I've had physics so it's pointless to argue because I don't feel like looking anything up. Lets just say you're right and I'm wrong and call it a day. Carry on...