Dlampe

I am looking for a new set of tires and the true height of tires has been discussed on many threads and so has weight but how does this play into performance. Tires in the 35 to 37 inch range probably truly range from 33.5 to 36.8 and the weight can also range from 65 to 95 pounds. If a "35" weighs 90 pounds and a "37" weighs 79, which tire will suck more power out of my rig?

Interested in your thoughts.

Rob 12B1P

Other things to consider are rolling resistance and wind resistance. I would think in general the larger tire (more leverage working against you, more wind resistance) would be the bigger power sucker as long as they are somewhat close in weight. Now how heavy a 35 needs to be before it sucks up as much energy as a larger tire I have no idea.

scubatech

The 37" inch tire will affect your gear ratio more than a 35" tire. The tread pattern will make a difference too. You may not need a M T tire for your type of wheeling.

Dlampe

I have a pretty heavy 35 now which weighs about 80 pounds and this tire would need to stretch to get to 34 inches. I was looking at a 37 that weighs about the same. Right now I have no problem with the performance of the Jeep with the 3.6 and 4:10 gears. Like may of us, I was thinking of going to 37's but honestly it's mainly for the look. I would like a tire that's an honest 35 or maybe 36. My 35's take me anywhere I need to go. I was hoping that the 37's wouldn't hurt the power to much but that doesn't sound like that's realistic.

GJeep

Increasing the wheel diameter is the most influential factor.
Much of the tire mass is concentrated at the tread. Even if a 35" and a 37" had the same weight, just moving the tread by 2" outwards, demands more of the engine power to move it (and of the brakes to stop it).

The effect of added air resistance, because of the somewhat larger 'front', would be much smaller, especially at regular Jeep speeds.

While placing the mass at a larger diameter demands more power from the minute the Jeep starts moving, air resistance it negligible below highway speeds.

That's one of the reasons why I chose 35"s rather than 37"s. With 4.1 gear ratio, I don't feel a lack of power.

Dlampe

I though this might be the direction the thread would take. It's really hard to justify 37's for a DD that only sees 6 -10 off road trips a year. I think I should focus on a good 35 inch tire and go that direction.

Now, who makes the best lift?

GJeep

I offroad more than that, and still preferred 35"s -- there's very little that 37"s can do but 35"s can't.

Best lift? Well, you've just opened a Pandora box...
The sky (and bank account) are the limit... but you probably mean a bolt-on lift.
I have the Full traction 4" lift, plus their CRC Link (which improves directional stability & steering), and Fox shock w/ reservoirs. I'm happy with it. Very good overall handling.

Though I have a relatively soft ride, I consider Metal Cloak dual-rate coils.

mtnxr

3 months ago I swapped 35 Nitto trail grabbers on 20" wheels for 37 BFG KM2's on 17" wheels and saved 24lbs per corner and gained a little height, maybe 3/4". The performance around town from the weight savings is very noticeable. The acceleration from a dead stop was considerably better based on seat of the pants and the computer showed a gain in MPG running around town with the computer reset for the tire size. Also, the Jeep just responds better all around, steering, suspension control on washboards etc. The Nittos were E rated and the BFG's were D rated which is another improvement for sure. This is on a 2010 3.8, Automatic 5.38 gears.

MOPWR2U

Keep in mind that tire manufacturers advertise the diameter of the tire, and not the height of the tire. The height of the tire is affected by many things that they don't have control of, such as the weight of the vehicle, and air pressure in the tires, to name a few. My Toyo MTs have a 34 7/8" diameter, which is pretty close to their advertised 35" diameter. But they are only 34 1/4" tall with the weight of the Jeep on them.

Also keep in mind that traction, and tire durability, may trump other factors when you are out there in the back country, especially if you go four wheeling alone much of the time. I've cut sidewalls on BFGs, Goodyears, Cooper, and Dick Cepek tires. I've never punctured a Toyo, ever. That means a lot to me, so I'm running Toyo's on this Jeep.

As for suspension lifts, and build toughness of the rest of your Jeep goes. Build for more than you think you might need. In my case I built my Jeep to be strong enough for 37s, and I even have enough tire clearance for 37s. I could run 37s without changing a thing. But I put 35s on the Jeep, so hopefully when I get in a bind, traction will be the weak link instead of one of the components on my Jeep.