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Discussion Starter · #1 ·
IF going from 265s to 285s lowers gas mileage, I assume because of weight and footprint, would a taller but not wider tire be better for MPG? If so how safe would that be?
 

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IF going from 265s to 285s lowers gas mileage, I assume because of weight and footprint, would a taller but not wider tire be better for MPG? If so how safe would that be?
You are correct that the weight and contact patch are what is lowering the MPG. Giong taller at the same width will also add weight in most cases and therefore also reduce your MPG. Going from a stock 31" tire to a 33" will raise your CG by an inch. This will effect your roll center a bit but certainly within reason.
 

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Dustin you are 13 years old, perhaps you should not make such comments until you actually know what you are talking about.

Dustin who? I am not 13, I am not Dustin, Probably old enough to be your dad. And yes, the great thing about this forum is that people post about things they have no clue about.:cheers:
 

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Discussion Starter · #6 ·
You are correct that the weight and contact patch are what is lowering the MPG. Giong taller at the same width will also add weight in most cases and therefore also reduce your MPG. Going from a stock 31" tire to a 33" will raise your CG by an inch. This will effect your roll center a bit but certainly within reason.
So you think a 285/75/17 might cut the mileage damage in half vs. a 285/70/17?
I wonder if anyone has tried this.
Thanks for the responses.
 

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So you think a 285/75/17 might cut the mileage damage in half vs. a 285/70/17?
I wonder if anyone has tried this.
Thanks for the responses.
As far as I know, you'd be the first. Another thing you can do is look for harder rubber. In either case, you are sacrificing traction, so keep this in mind.

I wouldn't bet on half, though. The FJ is still a brick.
 

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Dustin you are 13 years old, perhaps you should not make such comments until you actually know what you are talking about.
Dustin who? I am not 13, I am not Dustin, Probably old enough to be your dad. And yes, the great thing about this forum is that people post about things they have no clue about.:cheers:
I think we have two separate members here...

leadfoot and Lead Foot (Dustin)....

this could get confusing...lol
 

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As far as I know, you'd be the first. Another thing you can do is look for harder rubber. In either case, you are sacrificing traction, so keep this in mind.

I wouldn't bet on half, though. The FJ is still a brick.
Why would he be sacrificing traction?
 

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The size of the contact patch is a product of several factors - tire size being only one. If the pressure and weight are constant, the contact patch will be the same for a tall and wide tire... just different shapes.

And that ^ is yet another example of well articulated guess work in the form of a confident answer often found on forums. I really have no clue If I'm correct... but I think I am... I think.
 

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You are correct Matt, I sent leadfoot a PM with appologies and deleted my original post
 

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Discussion Starter · #14 ·
Humm, I thought 285/70 and 285/75 were just as wide, just different height. But what do I know, I am waiting on NCFG to correct me.
You are correct. 285 is the distance between the sidewalls.
The hight is 70% or 75% of that.
 

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Humm, I thought 285/70 and 285/75 were just as wide, just different height. But what do I know, I am waiting on NCFG to correct me.
So it is a public apology you require?

I am sorry I took you as Lead Foot, and it is NCFJ:wave:
 

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So it is a public apology you require?

I am sorry I took you as Lead Foot, and it is NCFJ:wave:

:wave: No apology needed, although I already accepted the apology. No big deal. I just wanted your opinion on the Tires issue.:bigthumb:
 

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IF going from 265s to 285s lowers gas mileage, I assume because of weight and footprint, would a taller but not wider tire be better for MPG? If so how safe would that be?
Going taller but thinner will not be as costly on gas as if you were to go wider, but only to a certain extent. When you get too tall where your gearing is affected, you'll find the FJ downshifting to up hills more then it did before. You could also get into situations where you're lugging the engine. The concensus of where regearing is needed to recover power and mileage seem be around 35 (overall diameter). Personally I feel even at 34, the gearing has already be altered enough to think about regearing. My true OD is probably 33.5 and FJ now downshift in certain climbs where it didn't before. The heavier tire probably is a factor too. Another thing that will affect gas mileage (in addition to weight, contact patch, compound, and OD) is the tread pattern.
 
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