Tahs (or tyres for dem norfern folks)
Posted: Tue Jun 15, 2010 1:26 pm
What size tahs do I need?
"What are the biggest tires I can put on with what my suspension lift?"
A: It depends on why you want taller tires. If you want to look cool, slap on the biggest set you can fit under the guards and ignore the rubbing. If you want better off road ability, read on. I suggest you keep your stock tire size and go for mud tyres unless you want to spend money to do the job correctly. (I'm not a full-bore suspension expert, but I do know about suspensions and lifting, so I'll just rant and rave a little here.)
First off, ask yourself: "Why do I want bigger tires?"
All tall tires buy you some additional clearance. On a Toyota 4x4, clearance isn't usually the weak link in off road ability, unless you spend a lot of time in deep mud, deeply rutted roads, or deep snow. Even if you do spend a lot of time in "deep dodo" the money can be arguably better spent elsewhere with better gains, there are other options. Here are several reasons to think before going larger tyres:
You'll lose low-end torque, because you'll effectively change the gear ratio. Each rev of the engine will turn the wheel the same number of degrees as before, but since the radius is greater, you'll be turning more circumference. You can change your axle gears.
For the reason above (unless you put on the new axle gears), your speedometer will read low. And sometimes even with the new gears it may still be a little off.
Bigger tires are heavier, and the weight is all unsprung, so it will beat your suspension harder, and can make for a rougher ride.
I think it's also rougher on the brakes, but they should still pull you up just be aware if you are towing that they are working harder.
Wider tires can cause a little wandering on the pavement and increase your rolling resistance. You'll pay for this at the gas pump.
Your wife, girlfriend, or whatever, will complain that it's harder to get into the truck (this could be a good thing!). Don't underestimate the grief this could cause you. In the end tho, I still have my rig.
Also with bigger tires your center of gravity will be higher, making you less stable in turns, unless you get tires that are somewhat wider, in which case you'll need fender flares to keep from attracting the boy's in blue, especially in the rain.
You won't usually get any extra traction over standard tyre sizes except in situations where you'd otherwise be high-centered or scraping the diff. The truth is, if traction is your goal, get a traction aid for the rear (LSD, posi or locker) and keep the stock tire size with mud pattern or if you prefer, get a winch. In fact, a lot of people recommend getting a winch first, because a locker tends to only get you further into the muck where you get REALLY stuck and then really wish you had that winch... a winch is also easier on gear and can be moved to another 4wd or still used when you do the lift and larger tyres.
In summary, if you're not prepared to spend more money or are just out to impress get large tyres. I'd spend the money in getting a winch, protection and lockers at both ends before a suspension lift and tyres. Then you can spend a lot of time pulling out your friends with tall tires and open diffs. If you really want tall tires, you'll need to spend some money to re-gear the axles and if you're going to go through the trouble and expense of regearing your axles, you might as well gear 'em for really tall tires, and then you'll need a lift to clear them.
"What are the biggest tires I can put on with what my suspension lift?"
A: It depends on why you want taller tires. If you want to look cool, slap on the biggest set you can fit under the guards and ignore the rubbing. If you want better off road ability, read on. I suggest you keep your stock tire size and go for mud tyres unless you want to spend money to do the job correctly. (I'm not a full-bore suspension expert, but I do know about suspensions and lifting, so I'll just rant and rave a little here.)
First off, ask yourself: "Why do I want bigger tires?"
All tall tires buy you some additional clearance. On a Toyota 4x4, clearance isn't usually the weak link in off road ability, unless you spend a lot of time in deep mud, deeply rutted roads, or deep snow. Even if you do spend a lot of time in "deep dodo" the money can be arguably better spent elsewhere with better gains, there are other options. Here are several reasons to think before going larger tyres:
You'll lose low-end torque, because you'll effectively change the gear ratio. Each rev of the engine will turn the wheel the same number of degrees as before, but since the radius is greater, you'll be turning more circumference. You can change your axle gears.
For the reason above (unless you put on the new axle gears), your speedometer will read low. And sometimes even with the new gears it may still be a little off.
Bigger tires are heavier, and the weight is all unsprung, so it will beat your suspension harder, and can make for a rougher ride.
I think it's also rougher on the brakes, but they should still pull you up just be aware if you are towing that they are working harder.
Wider tires can cause a little wandering on the pavement and increase your rolling resistance. You'll pay for this at the gas pump.
Your wife, girlfriend, or whatever, will complain that it's harder to get into the truck (this could be a good thing!). Don't underestimate the grief this could cause you. In the end tho, I still have my rig.
Also with bigger tires your center of gravity will be higher, making you less stable in turns, unless you get tires that are somewhat wider, in which case you'll need fender flares to keep from attracting the boy's in blue, especially in the rain.
You won't usually get any extra traction over standard tyre sizes except in situations where you'd otherwise be high-centered or scraping the diff. The truth is, if traction is your goal, get a traction aid for the rear (LSD, posi or locker) and keep the stock tire size with mud pattern or if you prefer, get a winch. In fact, a lot of people recommend getting a winch first, because a locker tends to only get you further into the muck where you get REALLY stuck and then really wish you had that winch... a winch is also easier on gear and can be moved to another 4wd or still used when you do the lift and larger tyres.
In summary, if you're not prepared to spend more money or are just out to impress get large tyres. I'd spend the money in getting a winch, protection and lockers at both ends before a suspension lift and tyres. Then you can spend a lot of time pulling out your friends with tall tires and open diffs. If you really want tall tires, you'll need to spend some money to re-gear the axles and if you're going to go through the trouble and expense of regearing your axles, you might as well gear 'em for really tall tires, and then you'll need a lift to clear them.