2008 Toyota Sequoia

[Taylor95]

Originally Posted by hayden55

I'm running 245/75/17 LRR tires from a jeep on mine. I'm super gear limited but they do okay. Your transmission is much better so they would do excellent on yours. My dilemma is torque converter doesn't lock until 45mph now and the rpms at 70 are still above 2000 RPM lol.

mpg from 265/65/17 to 245/75/17LRR was about 5%

So on Prius i try and stay below 45mph and on Sequoia i try and stay above 45mph lol.

You saw a 5% gain after adjusting for the speedometer difference between the different setups?

Do you happen to know the amount of weight reduced when you made the switch?

[hayden55]

Originally Posted by Taylor95

You saw a 5% gain after adjusting for the speedometer difference between the different setups?

Do you happen to know the amount of weight reduced when you made the switch?

Yup. I have a scan gauge so i make note of it. 28lb difference since both are listed on tirerack.

[Taylor95]

Originally Posted by hayden55

Yup. I have a scan gauge so i make note of it. 28lb difference since both are listed on tirerack.

Do you think a greater gain could be had by getting a setup that is lighter but the same diameter? I should be able to cut out 10 lbs per corner by getting different wheels and tires.

[hayden55]

Originally Posted by Taylor95

Do you think a greater gain could be had by getting a setup that is lighter but the same diameter? I should be able to cut out 10 lbs per corner by getting different wheels and tires.

By weight alone you probably wont be able to measure a difference.

[Taylor95]

Originally Posted by hayden55

By weight alone you probably wont be able to measure a difference.

Lol, but you said you got a 5% gain by reducing tire/wheel weight by 28 lbs.

[hayden55]

Originally Posted by Taylor95

Lol, but you said you got a 5% gain by reducing tire/wheel weight by 28 lbs.

I actually never mentioned weight until you asked.


"mpg from 265/65/17 to 245/75/17LRR was about 5%"

But yes my main point is mpg is gained by reducing width and friction
265 STD -> 245 LRR
and if you're vehicle isn't geared numerically low enough going to a taller tire helps.
30.56" -> 31.47" (+3%) (drops RPM for me above 45 mph but still 2000+ RPM at 70 )
I assume 90% of the gain is from width, frontal area, and gearing decrease. Maybe 10% of the gain or less is from weight (Less than 0.5% which i consider unmeasurable)

[Taylor95]

Originally Posted by hayden55

"mpg from 265/65/17 to 245/75/17LRR was about 5%"

But yes my main point is mpg is gained by reducing width and friction
265 STD -> 245 LRR
and if you're vehicle isn't geared numerically low enough going to a taller tire helps.

I think I have found the perfect solution. My Sequoia has the tow package, which means that it has a 4.30:1 gear ratio in the differential. The regular Sequoias have a 3.90:1 gear ratio that I could get.

I would want to keep the overall ratio close to stock (to retain towing capacity), so I will reduce my tire size.

My stock tire size has a 31.8" diameter and it has a 275mm width. I would need to go down to 29" for gearing to stay unchanged.

I don't want my tires to be too small, so I found a 30" tire to suit my needs. The 255 65r17 tires are much skinnier and they are eco-focused. When paired with the 17" wheels I found, the overall weight goes from 80lbs down to 57 lbs, a 23 lb difference! That would be a total of 92 lbs of rotating mass removed from the car.

I think this is the most optimal tire/wheel/gear combination that is possible with the Sequoia, and I think it would net substantial mpg gains.

[mpgmike]

Is yours 2 or 4 wheel drive? If 4X4, you'll need to change both rear AND front gears. There's supposed to be a slight difference between the front and rear, but not that much.

[Taylor95]

2WD!

Regearing would be twice as expensive if it was 4WD-not sure if I would consider it then.

Edit: To avoid making another post I want to update that my last tank averaged 20mpg!

[Taylor95]

So my giant 3-row SUV with a huge V8 just averaged 28.9 mpg on a ONE way trip from my house to a potential job (return trip will likely be 19 or 20).

There have been no additional modifications since my last post. It is very impressive how efficient these vehicles can be under the right conditions.