2014 JKU with 3.21 and 35s

[Jtmw]

Just so that it's clear for everyone else here, that's an advertised 35" tire as in, that's what it says on the sidewall but has an actual measurement of about 33", right?

4.88 gears with advertised 35's and with a 3.6L motor is a good combination that will bring you back to stock performance. :yup:

They measured to be just under 35, reason for 4.88 is I still have the 30 up front so going over 4.88 for me isn't an option at the moment.

Reading a little more gonna throw an edit under here and say I havent measured in the method you said above. Chances are my measurement was inaccurate.

 

[wayoflife]

They measured to be just under 35, reason for 4.88 is I still have the 30 up front so going over 4.88 for me isn't an option at the moment.

So, you're running a metric tire then? Again, 35" is what an advertised 37" tire measures and 5.13 would be a better ratio but, like you, I wouldn't run anything more than a 4.88 in a Dana 30.

Reading a little more gonna throw an edit under here and say I havent measured in the method you said above. Chances are my measurement was inaccurate.

Ah, give it another go and let us know. If you are seeing more of a 33" actual measurement with your advertised 35" tires, 4.88 will be a great ratio to go with. :yup:

 

[Jtmw]

Just ran out there and believe or not Eddie knows what he's talking about. My 35x12.5x17 Measured exactly 16.5 from center of hub to the ground. 16.5 x 2 = 33 :thinking: I bought 35's.

 

[wayoflife]

Just ran out there and believe or not Eddie knows what he's talking about. My 35x12.5x17 Measured exactly 16.5 from center of hub to the ground. 16.5 x 2 = 33 :thinking: I bought 35's.

:cheesy:

For what it's worth, you DID buy 35's and if you inflated them to 60 psi and measured the diameter from the highest bulges on the center of your tread and with it off of your Jeep (no weight), you probably would see a measurement that is close to about 35". Unfortunately, your gears and your speedometer only care about the distance from the center of your wheel to the ground - the "radius". Of course, tires are sold by their "diameter" and that's the only thing most people obsess over.

When it comes to lift kits, manufacturers ALWAYS refer to "advertised" size and NOT actual size. If you have a 2.5" lift, that will clear a set of advertised 35" tires which really means, an actual 33" tire. This would all be a no brainer if not for the fact that tires are also sold in metric sizes. This is where the size obsessive types get it all wrong as they only concentrate on "actual" tire size where they should be focused on what their inch size equivalent would be.

 

[IBeHeWhoIsJoshua]

if you inflated them to 60 psi

Oh man that'd be a horrible ride! Like riding on basketballs. Every time someone says their rig rides horribly I ask how much air is in the tires and it's always above 40psi haha

 

[Jtmw]

:cheesy:

For what it's worth, you DID buy 35's and if you inflated them to 60 psi and measured the diameter from the highest bulges on the center of your tread and with it off of your Jeep (no weight), you probably would see a measurement that is close to about 35". Unfortunately, your gears and your speedometer only care about the distance from the center of your wheel to the ground - the "radius". Of course, tires are sold by their "diameter" and that's the only thing most people obsess over.

When it comes to lift kits, manufacturers ALWAYS refer to "advertised" size and NOT actual size. If you have a 2.5" lift, that will clear a set of advertised 35" tires which really means, an actual 33" tire. This would all be a no brainer if not for the fact that tires are also sold in metric sizes. This is where the size obsessive types get it all wrong as they only concentrate on "actual" tire size where they should be focused on what their inch size equivalent would be.

I am dead :cheesy::cheesy:. Never thought about how it affects other people in the offroad marketing world. Thanks for the clarification, love learning new stuff.

 

[MedixJK]

they should be focused on what their inch size equivalent would be.

Ok so just to know what i am running, my 295/70-17 would be what as an advertised inch equivalent?

 

[wayoflife]

Ok so just to know what i am running, my 295/70-17 would be what as an advertised inch equivalent?

An advertised 35" tire. In fact, I typically consider anything from a 285/70R17 to a 305/70R17 to be in the advertised 35" tire range so you'd be right in the middle of that.

 

[noroad]

Thanks. Looks like I am going 4.56

Ya this will not be fun lol. I would take a step back and think about your jeeps future before picking a gear. question one is it an auto or standard? Question two how soon are you looking at getting a 44? question three is it you DD, if so how far?

If you have a standard and dont have plans for a 44 in the super near future i would do 4.88s. (i have this combo and it does pretty well, and keeps my dana 30 a little less mad well driving 80miles a day)

If you have and auto and have plans for a 44 really soon, I would get the 44 with 5.13s and then just regear the rear to save money. (i ran 3.21s on 37s for about 6 months and it blow but is doable for a sort time)

 

[MedixJK]

An advertised 35" tire. In fact, I typically consider anything from a 285/70R17 to a 305/70R17 to be in the advertised 35" tire range so you'd be right in the middle of that.

Awesome. Thank you. I cant believe how much grey area is covered when talking tire sizes. Craziness. Pretty sure i get it. so my buddy running 285s says he wants to go up to 35s... what he doesnt realize is that he really wants a tire that MEASURES 35. like a 37x12.50, or a 315... am i on the right track?

 

[wayoflife]

Ya this will not be fun lol. I would take a step back and think about your jeeps future before picking a gear. question one is it an auto or standard? Question two how soon are you looking at getting a 44? question three is it you DD, if so how far?

If you have a standard and dont have plans for a 44 in the super near future i would do 4.88s. (i have this combo and it does pretty well, and keeps my dana 30 a little less mad well driving 80miles a day)

If you have and auto and have plans for a 44 really soon, I would get the 44 with 5.13s and then just regear the rear to save money. (i ran 3.21s on 37s for about 6 months and it blow but is doable for a sort time)

Well put and I totally agree.

Awesome. Thank you. I cant believe how much grey area is covered when talking tire sizes. Craziness. Pretty sure i get it. so my buddy running 285s says he wants to go up to 35s... what he doesnt realize is that he really wants a tire that MEASURES 35. like a 37x12.50, or a 315... am i on the right track?

Yes. You definitely got it.

 

[JK LYF]

If you have and auto and have plans for a 44 really soon, I would get the 44 with 5.13s and then just regear the rear to save money. (i ran 3.21s on 37s for about 6 months and it blow but is doable for a sort time)

Good advice
I'm running about the same for about 2 months. 37s with 3.73. I did the flashcal and it's tolerable. Driving around town isn't too bad. I have NOT taken it out on the trails yet and am hesitant to do so. Getting the 44 with 5:13 in Jan. so I think I'll wait it out.

 

[Jk909]

just out of curiosity, how are you measuring them? there is some miss information out there about the proper way to measure tire height.

I measure from the floor to the center x2.

 

[NFRs2000NYC]

I had 3.21s with 33s on my last rig, and wanted to stab pencils into my eyes, I can't imagine 3.21s and 35s.

 

[NFRs2000NYC]

Yeah, I'm running 37x12.50's now (actual measurement of 35") and tested them out with 5.13's and thought it was a perfect match. I am now testing them out with 5.38's and, while the extra power is nice, the ratio is probably a bit on the high side. It sucks that it costs so much to swap gears but, I may go back down to 5.13's someday. You just don't know for sure until you've tested things out and I needed to know for myself what things would be like on a 3.6L vs. a 3.8L.

Your 4LO must be the bees knees though.

 

[IBeHeWhoIsJoshua]

I had 3.21s with 33s on my last rig, and wanted to stab pencils into my eyes, I can't imagine 3.21s and 35s.

Same feeling, larger pencils though.