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Discussion Starter #1
Picked up an 07 2 days ago . Has a 3in OME lift with bushwacker flares and currently has worn to the bone 35x12.5 17 on moto metal rims . I love the look but after much research Ive learned theres an mpg penalty for running large heavy tires . Also there's issues with highway travel and constant downshifting and a regear is expensive and out of my budget . Truck also has a vpr bumper and winch to add to the weight/mpg issue .

I think it looks awesome with the 35,s and Ive been told if I go too small ,especially with the bushwackers , it just wont look right so Im thinking Ill stick with the 35,s and try to find the lightest ones I can . Maybe even go to a 305 70 or 295 70 though Im not sure if they're much lighter than 35's . Im told 1.25 spacers would help in the "looking right" department if I go smaller . Not sure which way to go and cant afford to make a mistake so any help is greatly appreciated
 

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Sorry, I don't have any helpful advice on the tire issue, but I wanted to say welcome from WA. Throw up some pics and maybe an intro thread (y)
 

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Discussion Starter #3
I will shortly . I researched tire weights and the wrangler dura trac D rated 315 70 r17 weighs 61lbs as opposed to aTA ko2 35x12.5 E rated at 68lbs . From what I've found the stock wheel/tire weighs in the neighbor hood of 66 to 68lbs . The only thing I dont know is how much the moto metal rims I have weigh.
 

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You don't have a weight problem. You have a mechanical ratio problem. the 35s have re-geared the vehicle into a state it wasn't designed to operate in.

You won't improve your mpg or solve the under-gearing problem (constant upshifting) by using lighter tires or reducing weight. The only proper solution to your problem is to re-gear the rear diff or reduce the diameter of the tires.
 

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Discussion Starter #5
I can understand how that would be but reducing weight would help mpg at least a little . From what Ive read on the forum a re gear is out of my budget for sure . I'm thinking of going to a 305 70 17 to save at least a little weight . Rotational weight is a killer
 

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Discussion Starter #6
I was an ase certified mechanic in the 90s for around 10years but I've never messed with re gearing a differential
 

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There are a few rear differential re-gear kits out there for around $330. I'm no expert, but I think the 4.1 would work for 35 inch tires. And then there is cost to install.

Is that really cheaper than 4 new tires plus mounting? Also, lightweight tires aren't going to be as durable as standard tires, by definition.

You will still be lugging the engine if you continue to operate on 35 inch tires, so your mpg will still be bad.
 

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Don't forget that if it's a 4 wheel drive you need to regear both the front and rear differentials.
 

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Discussion Starter #9
No kidding. I'll have to investigate further . Installing the gears is not that big of a deal but if I remember correctly the tricky part is measuring backlash and something about shims.
Tires are down to the bone anyway so they're on the menu no matter what
 

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No kidding. I'll have to investigate further . Installing the gears is not that big of a deal but if I remember correctly the tricky part is measuring backlash and something about shims.
Tires are down to the bone anyway so they're on the menu no matter what
It is a big deal if you are installing ring and pinion yourself.


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Discussion Starter #11
If I can put a clutch in a mini cooper in my garage by myself . I'm sure I could handle it 😁
 

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Frankiev,
Welcome and congrats on your FJ purchase.

Theoretically you are correct in that a lighter tire/wheel combination would provide better gas mileage but not enough for you to notice. 35's are tall for your stock gearing. I do Not recommend changing out the differential gears yourself if you don't have experience doing so. I have wrenched on vehicles all my life and personally changed out gears on solid axle vehicles I've previously owned but even with my experience, I would not change the gearing on my IFS FJ. Getting the backlash and pinion depth set correctly is critical. This is not a backyard, weekend modification. Search Youtube for any ring and pinion swaps on Toyota's to get an idea of what's involved.

Don't be concerned with what other people think your Cruiser should look like. Although I run spacers on my Cruiser, keep in mind that spacers add additional stress on wheel bearings. I recommend you consider running 33's.
 

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Discussion Starter #13
I appreciate the sdvice . I was considering 33s however I was advised that with the bushwackers that tire would look oddly small . Im considering 305s . At 33.8 inches tall i thought it might be a good compromise ,as a matter of fact the nitto 35s on there now are worn to the nub and they measure not quite 34 from the ground to the top . They look fine so ....
 
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