fo_runner

Hey all, I have a 2000 3rd gen with the 16'' rims, and I just wanted to ask if LT265/75R16 tires will fit on my truck, even though the manual says my 4runner requires P265/70R16 tires. I already know that LT has a higher weight holding capacity than P.

Whats the difference with the /75 and the /70?

Your help is appreciated,

ASU4runner

Search is so helpful.

But anyway, here ya go...
265/70 is the factory 16" tire size on a 3rd gen. The overal diameter of this tire is about 30.5" The 265/75/16 is about 31.5" in diameter. The 75 and 70 numbers are known as the aspect ratio of the tire -- sidewall height (70 or 75) v/s width (265).

You will have no problems running a 265/75/16 tire on your 4runner. Only difference might be a slight loss in your gas mileage. But not noticeable.

midiwall

Ditto... I ran 265/75R16's pre-lift with no problem. You'll find that your speedo will be dead-on, and your odometer will be 4% low (multiply the reading by 1.04 to get actual miles driven).

fo_runner

I just put on the LT265/75R16 tires on the rear, and dang, they look wayy cooler than the weeney stock tires. The truck has a different stance now, the rear is taller than the front. I'll put on coil spacers in the front, if i have the time to do so.

How much of a MDG drop should i experience?

Localmotion

hardly noticable. maybe 1

Travs97

yes it will work and i think it looks good just my 2cents

fo_runner

Will the 265/75's rub if I put them in the front also, or will i need a minor lift?

midiwall

Whoa... back up a half step.

Are you 4WD? If so, you REALLY don't want to run different tire sizes between front and rear.

fo_runner

Yes, i am 4WD. But I haven't used 4WD yet with the new tires on the rear. Whats wrong with running different tire sizes on a 4WD?

Is it because the 4WD will think its running on stock tires or, the back tires will roate faster than the front tires?

tc

The back tires (being larger) will actually be rotating SLOWER than the fronts, and there is no "slippage" in the transfer case to accomodate this speed difference, putting huge strain on the drivetrain components. If you were on a slick enough surface that the drivetrain stresses were not critcal, I would imagine it would have some pretty treacherous handling.

midiwall

Yeup...


It's the same situation as if you had different gear ratios in the front and rear diffs. It's a horrible load on the diffs and transfer case. You can tear things up REALLY quick and create a nasty (read "expensive") mess.

Even without engaging 4WD you've created the issue that the front tires are spinning faster than the rear. That'll create a bit of a steering geometry issue, but since you only went up 1", it's not too bad.

You REALLY want to either put the old tires back on the rear, or do the same to the front. And whatever you do, do NOT engage 4WD until you get both ends equal.

fo_runner

Since the tires are only different by 1'', there shouldn't be "That" much of a strain on the drivetrain. But I intend on driving my truck on snowy conditions, I hope this would reduce the stress in the drivetrain.

What would really happen if I put it on 4WD, even thought the conditions are slippery?

mike_d

of course it'll be a huge strain on the drivetrain. the front tires are 30.5" and the back are 31.5" that means that in one mile the front tires turn 661 times and the rear tires will turn 640 times. which means that some how the drive train will need to allow the tires to slip enough to make up for 21 revolutions in only 1 mile! that's crazy to expect that to work. in 4wd the front and back tires (axles) need to turn exactly the same speed - that's why even with the same size tires you don't run 4wd on dry pavement, just going around a turn is enough to stress the drivetrain.

on dry pavement you'll break something, probably before you get out of your driveway.

on snowy/icy conditions, this will be worse than just driving with two wheel drive. in 2wd you'll atleast have the rear tires trying to push you along. in 4wd you'll have the case where the front tires will try to slow you down (because they're smaller) and the rear tires will try to speed you up. this will probably cause both tires to lose traction and you'll have worse grip than if you were in 2wd. and if i was your insurance company i wouldn't pay if you were in an accident because you clearly were doing something that the truck was not intended for. i want to be very clear here: DO NOT RUN 4WD WITH DIFFERENT SIZE TIRES ON THE ROAD - EVEN IF IT IS SLIPPERY - IT WILL BE MORE DANGEROUS THAN 2WD (AND YOU COULD STILL BREAK SOMETHING)

the only time that this would be acceptable, and i use acceptable lightly, is if you were in many feet of powder (or deep mud) and your wheels would barely be getting any traction anyway. then maybe you'd get some extra help from the front tires. but any time that you're actually expecting the tires to grip, this would be a terrible idea.

get new tires (of the same brand and size) for the front. i'm sure if you search the web for more info, you'll even find that you shouldn't even run the same size tires of different brands. there's enough variation in the sizes that that can cause problems.

midiwall

Hey Mike, tc... forget it.

Obviously Mr. Fo knows more than we do about how the drivetrain works and what will happen when the front doesn't match the rear.

Mr. Fo... Please prove us wrong. You're right, an inch won't make a difference. Please drift out into the street, drop the truck into 4WD and drive... Gently, jam on it, whichever - your choice. Got a buddy to hold a video camera? Cool. Fire it up, make sure the sound's recording.

Include pictures and a scan of the repair estimate when you get a chance.

Localmotion

in other words, get the same tire size unless you are driving a hotrod. and no, they will not rub up front either.

fo_runner

Alright. Alright, if its such a huge strain on the drivetrain, then i'll change the front tires too, I finally understand what would happen if I didn't change the front too. Sorry for making you guys have such a PITA. If it wasn't for you guys, I would for sure be grinding up gears in no time.

THANKS ALOT, for saving my truck from distruction

midiwall

Oh no, really.. We REALLY wanna see/hear/smell/taste what happens when you chuck it into 4WD.

Please? C'mon, be a sport!

tc

If he can hold off for snow before engaging 4WD, I bet he spins it into the ditch before he could break anything (which is to say about as soon as he lets off the brake).

Hey fo_runner - we weren't being mean, just didn't want you to trash your truck. By asking the "stupid" question, I bet you saved several other people's trucks too.

Would LOVE to see the video though...wonder if we could take up a collection to replace the parts that would break.

Oooooh - what if both front and rear diffs were locked and you tried this!

fo_runner

You guys crack me up when you joke around. Sorry guys, i'm not risking my truck to be a ginea pig for you guys, thats just WRONGG!!

But I remember one time when I grinded gears when I forgot to shift into neutral to change from 4LO to 4HI. Damn, did it sound terribly cool.

slow_key

not very sporting of you is it