Using a 255/85/16 as a spare for 285/75/16?

So, I have a set of Interco Trxus MT's in 255/85/16 with about 50% tread left and I am running 285/75/16's on my truck. I am in need of a full size spare and was curious if I could use the 255 as a spare. Is the diameter of each tire close enough to not cause any harm to the drivetrain?

 

close enough. obviously no 4 wheeling but it'll get you there without a problem

 

Yeah that's what I was thinking

 

in the event that you get a flat up front...it may not be a bad idea to swap out a rear and run your spare in the rear... maybe it wont matter because its not that much bigger


But I think it'd be fine too either way

 

As long as you are not in locked mode it should be okay. These vehicles are actually 1 wheel drive in 2wd mode and 2 wheel drive in 4wd mode, unless you have a locker. Obvioulsy at freeway speeds and on a longer trip a near perfect match is best but........

Another alternative is a puncture kit and some sort of air system, which could be as simple as a high end bicycle pump. Sometimes simple is better in the woods. Unless it is tear or a sidewall injury, a puncture kit can fix most holes in a snap and you wont even need a spare.

I am running Wild Country XTX 285-70-17s on 17" American Racing Mojave wheels with 4.5 inches of backspace. My biggest challenge was finding a comparable tire to keep under the truck in the spare position that had a close diameter (the tires I am running have an overall diameter of 32.8"). I cant keep the spare in the back like some people do as I commonly use the back for camping equipment for my family - I have a camper shell on the back. I dont have the $$$ for a swing gate, but that would be really nice.

I tried several different tires and found that a TOYO M55 235-85-16 was the best of all worlds (http://toyotires.com/tire/pattern/m-55). My reason is this tire is narrow enough not to hang down, and is narrow enough not to get hung up on the UCA in the front position, it is 32" in diameter, close to the 32.8 of the other 4 tires. If fits nicely. I had to bend the spare tire mounts out of the way, so had to use a tie down strap to hold it back away from the axle, before I used the tie down strap it was hitting the differential at full articulation and on washboard. I plan to fab some new mounts, but I honestly feel this is the tallest, narrowest, tire that will fit under the back while still maintaining rear axle articulation and clearance.

Good luck!

 

Nice! That looks like a pretty skinny tire you got there. I don't have a locker but I have the auto LSD. I'm thinking it could be alright to run the 255/85/16 but if the size is off a little would it make my LSD be constantly active?

 

I think you may be correct in that case. I have a 6speed standard and dont have electronic assist, so not sure about that. Howevor, I also own a subaru, which has electronic torque proportioning, which is run by a light sensor in each wheel (similar to the ABS system), and it freaked out at me for driving a longer (about 30 miles) on a low air partial flat tire - had to have the dealer re-set the check engine light. As long as you are running 2wd with the electronic assist turned off, it should be just fine. Friggin electronics.....love them when they work, but sometimes the moon and sun need to align!

 

I have the same transmission as you. Its not electronic its a mechanical Limited slip than engages when there's tire spin

 

What year/model is that? TRD Sport? I am always interested in the different combos out there and how they operate as compared to mine (so I know what to buy next time!). Electronic limited slip would be nice. Is that similar to the electronic stabilization from the 4runners?

 

I read it right this time. MECHANICAL limited slip. This is like the posi trac rear end in my 70' CJ-5. Should not be a problem as these usually only are triggered when there is a sufficient difference in wheel speed. That is one wheel needs to be spinning significantly faster than the other for the "lock" to be activiated, otherwise the vehicle would never be able to turn a sharp corner or the differential would lock each time you turn sharp. It is probably set at a rate just above the sharpest turning radius so it will not activiate under "normal" activity. In this case I would not think running a close-in-size, but smaller tire would cause a "lock" effect.

Is that the TRD model, or the general 6 speed 4wd? I have a TRD. IMO, the TRD is a waste of money, the suspension sucked, and I had to replace it all anyway. Only benefit is the locker, but you could probably get a better aftermarket one for less $$$. If I had gone with the standard package instead of the TRD, the money saved would have paid for the suspension upgrades!! Just my $0.02

See http://en.wikipedia.org/wiki/Limited_slip_differential for more info on lockers.

 

Here is a better summary of the activation of the LSD in the Tacoma: http://www.tacomaworld.com/forum/te...uto-lsd-explained-easy-understand-i-hope.html

 

It is a TRD sport and you are right about that package being a waste of money. I barely put 5k on the stock suspension haha. I think I'll get one of my spares mounted and see how it works out.

 

@Kauluwela -
Thank you for the informative post! How come you had to bend the spare tire mounts out of the way? Does this have something to do with the tire being narrower or taller?