One of the first things people ask around here is
how much lift is required to run a certain size tire, followed by
which lift performs best offroad.
The proper answers are
depends on the type of lift, and
lifts don't improve offroad performance.
Large tires and increased suspension travel improve offroad performance. For example, look at the Hawaiian Tundras and Tacomas--very large tires for running in bottomless sand, and Suzuki Samurai owners with 31" tires and three feet of suspension travel. The best offroad rigs combine these two attributes--moon buggies with no 'lift' but 44" tires and several feet of suspension travel at both ends.
As this excellent writeup at
Trails Less Traveled states, "The right size tire for any truck is the one that fits at FULL COMPRESSION." Basically, that means if the lower control arms are resting against the bumpstops, the biggest tire you can run is the one you can still turn lock to lock without rubbing anything.
The most common type of lift raises the truck via a modification to the coilover assembly, and at rest a larger tire will fit and turn without rubbing. Since the tire can still travel the full distance upward, it will rub the front of the cab when the wheel is turned and the tire is compressed. Sure, the truck is lifted and has bigger tires, but bigger tires are useless if you can't twist up the truck and then turn the steering wheel without eviscerating the wheel well.
This is why a simple spacer lift still rubs for many people, and why it will always rub unless you continue to run
no larger than a 265/75/16 or equivalent tire. A coilover lift allows you to "get away with" a larger tire, until you actually need to flex the truck. All it really does is improve the breakover angle. In order to really make use of a larger tire, the wheel well must be
trimmed to make room for the tire when the suspension is compressed and the wheels are turned. Since tire size is ultimately limited by the body mount at the rear of the front wheel well,
a 35" tire can be fitted without lifting the truck. Body lifts allow these tires to be fitted without trimming the wheel well, but offer no other direct benefit than removing cab/tire interference at the rear outer corner of the front wheel well. Drop bracket lifts will allow the tire to clear the body mount only because they move the maximum compression point of the tire lower on the frame, and again offer no other direct benefit than making your truck the tallest on the lot. If you never need to flex the suspension, a drop bracket may be sufficient--a beach truck can get away with this setup, whereas on the trail the same truck would be hampered by the combination of
high CG and
limited articulation and will be outperformed by an unlifted rig (
low CG) running longer shocks and uniballs (
increased suspension travel) and properly trimmed for the same larger tires.
So basically,
if you want to improve your truck's offroad performance by running a larger tire, ensure that your truck is capable of turning that tire lock to lock in the conditions you'll experience offroad. If you're only ever on the beach, that may only require a bolt-on drop bracket (or a wad of hockey pucks
), but on the trail that requires fully cycling the suspension while the wheels are turned to full lock on each side. The cab may not be the only point of interference, the stock bumper will interfere with anything larger than a 265/75/16 or equivalent tire and most aftermarket bumpers will interfere with anything larger than a 285/75/16 or equivalent.
Search the
Handling, Suspension and Axle forum for posts on
uniballs,
longer coilovers and
replacement spring packs. Also search for
trimming and
pinch weld modifications, that topic is generally in the
Offroad Forum. In general, avoid blocks, body lifts, spacers and drop brackets unless you need a quick fix to complete a setup, cannot/will not trim the cab, or have a leased vehicle that must return to stock in the future.
Trimming the pinch weld back to the cab will allow a Tundra to flex and turn a 285/75/16 or equivalent. The bumper needs to be trimmed.
Trimming the p/w and tubbing the cab will allow a Tundra to flex and turn a 315/75/16 or equivalent. With longer arms (LT length), significant trimming and cagework, a 37x12.5 tire can be made to fit. Without the longer arms, a 37" tire will hit the frame before full lock.
If you don't ever intend to flex and just need to get a few inches for the on-road offroad look, 2" of lift will generally clear a 285/75/16 or equivalent tire. 2" of spacer and 3" of body lift, or 2" of spacer and 4" of cradle lift, will generally clear a 35" tire.
(I suppose that means that if you're on the beach, the RCD 6" kit and a good trim+tub job might allow you to run a 40" tire, but that's just a guess...it will probably hit the frame when you turn)
IF YOU TRIM THE PINCH WELD be sure to resecure and seal the cut, particularly if you're on the beach or drive in salty winters. Herculiner is a great sealing material, just follow the instructions. The best way to resecure the pinch weld is by welding over the cut (remove everything flammable from the cab near the weld, and cover with a wet towel).