tires and gearing?

[kman55]

Hello I know that this has been covered before, but i still dont know the answer exactly. 'I have a 2000 2.7 I-4 completely stock, base model, and i have reached the time and funding for new shoes for the girl. I currently have 225/75 R15 and am looking at the possibility of moving up to 31x10.50 R15. I just dont like the look of the small tires on it now. I know they will fit, but i guess my question is will they run properly with my stock gearing. Which i dont know exactly what it is, i have 2wd automatic. I just dont want to mess up anything or the transmission. I do like the look of the extra height. Thank you all for any help. I just want to make an informed decision and keep her running as faithfully as she has!:banana:

 

[scottyb]

It looks like 225/75 R15 tires are 30.06" tall and 10.04" wide by the numbers. That's only a 3.13% increase in diameter to 31's. The only difference is you'll have slightly less torque at the wheels, but I bet you won't notice it. I have 7.6% difference from stock tire size and it's not bad. And they won't hurt your transmission. Enjoy the new tires:driving:

 

[02SE]

It looks like 225/75 R15 tires are 30.06" tall and 10.04" wide by the numbers. That's only a 3.13% increase in diameter to 31's. The only difference is you'll have slightly less torque at the wheels, but I bet you won't notice it. I have 7.6% difference from stock tire size and it's not bad. And they won't hurt your transmission. Enjoy the new tires:driving:

FWIW, P225/75R15 tires are approx. 28.3" tall, and 8.9" in width.

30.06" tall by 10.04" width, is getting close to the actual size of most 31x10.50R15's.

OP, I've never driven a 4 cylinder 3rd gen 4Runner, so my opinion is just speculation. I'd guess that you'll notice a difference in power, and a drop in MPG's. It would probably be tolerable though.

 

[scottyb]

FWIW, P225/75R15 tires are approx. 28.3" tall, and 8.9" in width.

30.06" tall by 10.04" width, is getting close to the actual size of most 31x10.50R15's.

OP, I've never driven a 4 cylinder 3rd gen 4Runner, so my opinion is just speculation. I'd guess that you'll notice a difference in power, and a drop in MPG's. It would probably be tolerable though.

I was going by just the numbers to get an estimate of the difference since I don't have those tires lying around to measure. In actuality you need to use the effective diameter due to the deformation of the contact patch of the tire like 02SE is saying yielding a different size than the numbers give you. I bet ~3% is close either way.

 

[kman55]

Thank you all, i have been looking at the 30x9.5 also, staying a bit closer to the 3% range, but im still undecided on what to do. The 225/75 just appear so small and ive noticed that no one else really has them on theirs. yet they also are mainly 6 cyl. Im just hoping the 4 can pull it all okay.

 

[Dous]

Thank you all, i have been looking at the 30x9.5 also, staying a bit closer to the 3% range, but im still undecided on what to do. The 225/75 just appear so small and ive noticed that no one else really has them on theirs. yet they also are mainly 6 cyl. Im just hoping the 4 can pull it all okay.

I've got 33's with the stock 4 cylinder gearing, and it's okay. Not fast, but just fine. With 31's you will hardly notice a difference

 

[kman55]

Is yours a 2wd automatic. Also just curious what kind. I'm kind of thinking about bfg at.

 

[kman55]

Okay i was trying to find the gearing and i believe the code for it is A02A. I found a website and it states that A02A is 3.58 gears. I have heard for 31's most use at least a 4.10. I feel like i will be very underpowered. Gearratiosanddiffs

 

[ChildrenOfBodom]

Nah, third gens never came with that ratio.

I'll bet you have 3.91's like i used to, 1999 2.7 2wd auto

 

[kman55]

Thank you for responding bodom. Do you think I would have to change anything to make the jump. Sorry to keep this thread going, I swear I just can't find anyone with this same hearing or anything! Your the first!

 

[ChildrenOfBodom]

Thank you for responding bodom. Do you think I would have to change anything to make the jump. Sorry to keep this thread going, I swear I just can't find anyone with this same hearing or anything! Your the first!

Nah, you'd be just fine throwing some 31" tires on there. You will definitely feel at least a little power loss, not gonna lie... but honestly, when I first did the 31" tires, I did not mind the difference. The speedo was also off, so you've gotta compensate to figure out your actual mileage... etc.

31" tires will feel like your 225's with some 4.30's, but 3.91's will still work. Factory differentials sell for pretty cheap, you can likely just buy a 4.30 or even a 4.56 ratio rear end from another 3rd gen if you want your power back.

I regeared to 4.56 when I upped to 32"s. I kept the same gearing with 33" tires because I swapped to a manual transmission. 4.56 on a manual feels like an auto would with 4.88 gears.

If you want to look into buying another differential, check Car-Part.com--Used Auto Parts Market. Search for a carrier. You'll be able to choose what ratio you want and it will give you dismantlers who have that particular diff in stock. That's how I found my 4.56 (rare OEM ratio) front diff. I'd say 4.30 would be just about perfect for you, you'd gain some power back and it would also correct your speedometer.

Just don't expect a world of difference... do it only if you're fine with spending the money.

 

[kman55]

Thank you so much! I really appreciate all the help! I know i have been asking alot, i just have no clue about gearing. This forum helps so much! Ill post some pics when i get them! Thanks again!:thumb3:

 

[l3igl3ang]

Dont know if it helps but i put 33 12.50s on my 88 4cly with stock gears and i got around all over the place im not sure what gears was in the 88s i think 410's but it it didnt have to much power loss couldnt do over 70 though but 31's should'nt have to much powerloss

 

[kman55]

That does help actually, thank you very much. I think i will go with the bfg A/T 31x10.50r15. If it is too sluggish then i will probably just re-gear. Thanks again everybody! The comments helped with my decision greatly.