My Jeep calls for 225-75-15 tires. If i would go to a 235-75-15 (more common size), they would be .50 taller. What would this do to my transmission? Why would they call out for such a weird size? I have a 3:73 gear ratio and now it shifts into 3rd gear at 45 mph under light load. If i went with the taller tires, it would shift sooner. Is this ok?
help with tire size
- Thread starter JonS
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some companies wont sell a higher tire than reconmended...but some will. i have an accord that came with stock 195/55 r 15 tires. i upgraded them to 205/60/r15 tires casue there is soo much wheel gap. there is almost no differnce but when i make a full u turn and let go of the wheel the whell kinda jitters..but this is due to the higher tire size..but it only does it once in a while and everything else is fine. as long as u have room under there u should be good. id do it.
That size was more common a few years back.
It would cause your speedometer to read slightly less than the actual speed you were going.
It would change your shift point to 46 mph, but the speedo would still read 45.
An alternative wouldbe to use a 235/70 which would cause your speedo to read slightly faster than you were actually going, but it would be closer to you original size.
Neither one would make noticeable difference.
http://www.smokemup.com/auto_math/tire_diameter.php
http://www.smokemup.com/auto_math/mph_range2.php
[ January 14, 2003, 12:34 PM: Message edited by: VaderSS ]
It would cause your speedometer to read slightly less than the actual speed you were going.
It would change your shift point to 46 mph, but the speedo would still read 45.
An alternative wouldbe to use a 235/70 which would cause your speedo to read slightly faster than you were actually going, but it would be closer to you original size.
Neither one would make noticeable difference.
http://www.smokemup.com/auto_math/tire_diameter.php
http://www.smokemup.com/auto_math/mph_range2.php
[ January 14, 2003, 12:34 PM: Message edited by: VaderSS ]
Tire Rack has a fair amount of that size.
if ur talking to me i felt no differnce...more grip and smoother ride though
Ok im what you would call a jeep nut... If you have a YJ (square headlights- 95-87) you can fit a 30x9.5x15" tire stock w/o lift. On a TJ (circle headlights- 97- newer) you can fit a 31x10.5R15 stock. Id suggest BFG AT's if you dont wheel it much, if ya do get the BFG MT's (they will last alot longer then the cheap mud terrains). If you have the 4 banger shifting will be more common... If you have the I-6 and its a 1990 or newer you shouldnt have any probs with a 31" tire. With you saying 3.73 gears id think you would have a TJ and the D44 package b/c they came w/ 3.73 although in the past the D35's had the 3.73 gears in em on occasion. Either way you can run 31's w/o a prob. I run 33's with a 4.0L/AX-15 (stick)/ NP231 (w/ 4:1)/ D30 and D35 (soon to be 8.8
) and 4.10 gears. I cruise quite nicely on the HWY and once i get a new rear axle ill be heading to 35's with my gears. Go for the largest tire size you can fit w/o a lift. Also take a look wt www.jeepsunlimited.com/forums but use the search feature first or youll get some rough replies. Happy jeepin
I do a lot of towing a 3000 lb boat in the summer. I do not want to lug the engine by having to big of tires on it. the 235 is easier to find than the 225. I have a 1995 Grand Cherokee with the 4.0 liter and the 3:73 gears.
[ January 16, 2003, 03:09 PM: Message edited by: JonS ]
[ January 16, 2003, 03:09 PM: Message edited by: JonS ]
I'll put it a different way.
It would be the same as if you went to a 3.66 gear, while retaining the 225 tires. To put it another way, the perceived torque would be reduced by less than 2%.
Honestly, I don't think you could tell the difference, I certainly don't think it would cause your engine to lug while pulling the trailer.
It would be the same as if you went to a 3.66 gear, while retaining the 225 tires. To put it another way, the perceived torque would be reduced by less than 2%.
Honestly, I don't think you could tell the difference, I certainly don't think it would cause your engine to lug while pulling the trailer.
Jon, Vader nailed it. I have that same engine and have pulled over 4000lbs on 32" tires with the 3.55's. You won't be passing many people but it works.
What's worse are the stock brakes. Braking is equally affected by tire size but stock ZJ brakes are a weaker point than the engine. You might want to consider stickier aftermarket rotors & pads.
David
What's worse are the stock brakes. Braking is equally affected by tire size but stock ZJ brakes are a weaker point than the engine. You might want to consider stickier aftermarket rotors & pads.
David
you think 3.66 overall is bad? The stock TJ's and YJ's with the 6cyl came with 3.07 R&P... i had 33's on those gears for a lil while and that really stunk. FWIW my buddy has 3.55's in his f-150 and can still spin his 35's
One more question i need answered about tires is the tread pattern. What is better for ice? A lug style like the all terain BFG, or the highway tread style of like a long trail BFG. I actually don't do any mudding (i wish i could) so i really don't think i need the big lugs. Aside from ice traction is i would like a quiet tire. I have a 95 Jeep Grand Cherokee 4x4. What tread should i look for?
thanks
thanks
Jon, I speak from recent experience. I have a Cherokee with the BFG Long Trails, a Bronco with BFG A/T's, and an Explorer with General Grabbers. The A/T's and Generals are much better on ice than the Long Trails. In fact, I wish I had put BFG A/T's on the Cherokee instead of the Long Trails.
Tire tread compound also enters into good ice traction, but my choice would be a tire with an aggressive and wide tread for ice. The flexible tread blocks seem to grip ice better than a street tread (such as Long Trails) does.
Tire tread compound also enters into good ice traction, but my choice would be a tire with an aggressive and wide tread for ice. The flexible tread blocks seem to grip ice better than a street tread (such as Long Trails) does.
the AT's last forever and will do anything EXCEPT MUD... for you it sounds like they are a great recipe.. 30x9.5 works and 31x10.50 look good and with a grand cherokee (ZJ) you can put a 2" spacer lift and 31's on it for next to nothing (price). If you dont want to deal with lift the 30x9.5's should fit the bill
Stay away from the long trails for icy conditions. I had aset on a Tahoe and they stunk when there was a little bit of ice, and were so so in the snow.
The BFG AT is a very good tire, although a little pricey. It sounds as though it would be a perfect choice here, and would look good too.
Other tires that have worked well for me around here are the Michelin LTX M/S (more of a street tire, if you like, that does very well in the snow), Michelin LTX AT (very quiet, good snow tire, and Bridgestone Dueler AT's have also worked very well for me.
The BFG AT is a very good tire, although a little pricey. It sounds as though it would be a perfect choice here, and would look good too.
Other tires that have worked well for me around here are the Michelin LTX M/S (more of a street tire, if you like, that does very well in the snow), Michelin LTX AT (very quiet, good snow tire, and Bridgestone Dueler AT's have also worked very well for me.
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