40's -vs- 42's..... Ready.. Discuss!

DavoSmith said:
Is there is a significant increase in off-road capability comparing 42" Nitto Trail Grapplers vs 40" Nitto Trail Grapplers on a Diesel Jeep Gladiator JT build?

I'm planning a significant JT build with 72.5" Dynatrac 60/80 ProRock HD axles, 5.13 gears, E-lockers front and back, PSC Steering Kit and either EVO or Rebel Offroad Long Arm suspension. Given the extra long wheel base and shallow departure angle of the JT, I'm assuming I could use the extra ground clearance and improved departure angle the 42s would provide. I'm wondering how much more capable the JT would be with 42" compared to 40" tires on the Rubicon and Moab, Sand Hollow trails.

Real world insight is greatly appreciated.
Click to expand...
5:13?…
 
Not sure why I just read this whole thread, I'm on 35s and don't have the money to talk about 40s VS 42s lol

However on anything but a Gladiator 42s look too big in my opinion. To me 37s are a big tire and 40s seem to handle just about anything. I don't think I can justify anything bigger than a 40 because there is no reason to sacrifice more power for no significant increase in performance. Especially for these guys with 4 bangers and gear ratios for 37s...
 
DavoSmith said:
Is there is a significant increase in off-road capability comparing 42" Nitto Trail Grapplers vs 40" Nitto Trail Grapplers on a Diesel Jeep Gladiator JT build?

I'm planning a significant JT build with 72.5" Dynatrac 60/80 ProRock HD axles, 5.13 gears, E-lockers front and back, PSC Steering Kit and either EVO or Rebel Offroad Long Arm suspension. Given the extra long wheel base and shallow departure angle of the JT, I'm assuming I could use the extra ground clearance and improved departure angle the 42s would provide. I'm wondering how much more capable the JT would be with 42" compared to 40" tires on the Rubicon and Moab, Sand Hollow trails.

Real world insight is greatly appreciated.
Click to expand...
Having personally wheeled both setups, I can tell you even with a diesel, 5.38's provide just enough power. As far as performance goes, I saw no significant difference between 40 and 42. If anything, with 42s, you need to go higher and you'll still rub big time unless you extend your bump stops. Of course, on a JT, trying to keep your rear pinion from binding at a full droop is more of a challenge as well especially if you're running coilovers.

That said, I am still running 42's with my 3.6L and they look great but I'll most likely drop back down to 40's when they wear out.
 
wayoflife said:
Having personally wheeled both setups, I can tell you even with a diesel, 5.38's provide just enough power. As far as performance goes, I saw no significant difference between 40 and 42. If anything, with 42s, you need to go higher and you'll still rub big time unless you extend your bump stops. Of course, on a JT, trying to keep your rear pinion from binding at a full droop is more of a challenge as well especially if you're running coilovers.

That said, I am still running 42's with my 3.6L and they look great but I'll most likely drop back down to 40's when they wear out.
Click to expand...
You running limit straps on that beast?
 
wayoflife said:
Having personally wheeled both setups, I can tell you even with a diesel, 5.38's provide just enough power. As far as performance goes, I saw no significant difference between 40 and 42. If anything, with 42s, you need to go higher and you'll still rub big time unless you extend your bump stops. Of course, on a JT, trying to keep your rear pinion from binding at a full droop is more of a challenge as well especially if you're running coilovers.

That said, I am still running 42's with my 3.6L and they look great but I'll most likely drop back down to 40's when they wear out.
Click to expand...
I’m so close to pulling the trigger on 42’s and this thread has me seriously considering not making the move and sticking with 40’s. @wayoflife are you still feeling the same way about the 42’s a few months into 2023?
 
azjtr said:
I’m so close to pulling the trigger on 42’s and this thread has me seriously considering not making the move and sticking with 40’s. @wayoflife are you still feeling the same way about the 42’s a few months into 2023?
Click to expand...
So, now that we're running Currie Antirocks, we're no longer seeing the kind of rubbing that we were previously due to the torsion bars limiting the amount of flex we have. Also, now that we're running EVO trailing arms, we now have our rear pinion angle always in line with our drive shaft and that's been a HUGE plus! Without these two changes, I think we'd be way more hot to trot into going back down to 40's. That's said, going smaller is still on the radar for us.
 
wayoflife said:
So, now that we're running Currie Antirocks, we're no longer seeing the kind of rubbing that we were previously due to the torsion bars limiting the amount of flex we have. Also, now that we're running EVO trailing arms, we now have our rear pinion angle always in line with our drive shaft and that's been a HUGE plus! Without these two changes, I think we'd be way more hot to trot into going back down to 40's. That's said, going smaller is still on the radar for us.
Click to expand...
I have heard you say before that you like 20 inch wheels with 40s. When/if you downsize the tire size will you keep the 20s?
 
wayoflife said:
If anything, this is the direction a lot of us went in - WIDER. As in, 40x15.50's.

main.php


Still one of my all time favorite setups.

main.php
Click to expand...
I like that set up too. Major fun.
 
azjtr said:
I’m so close to pulling the trigger on 42’s and this thread has me seriously considering not making the move and sticking with 40’s. @wayoflife are you still feeling the same way about the 42’s a few months into 2023?
Click to expand...

My personal experience is that 42s provide some advantage to 40s. It depends how hard of trails you do. There have been a few obstacles so far that freinds with similar built JLs have not been able to make. We are talking 9 rated trails bordering on buggy level here in Sand Hollow (Chain Reaction, Twister, Nasty half...) It's always been a matter of that 1" breakover advantage.


That being said, my Jeep sees 2-3 trails a week and 15-20k miles a year. My Nittos look as if they will last maybe 20k. I may end up going down to 40s just because of the cost and amount of use. I'm hopeful that new competition from Mikestar and Mickey may drive the price down. I don't know if $3700 a year in tires is worth it 🤣
 
Not to bring up an old thread, but I lost my mind and decided to try some 42's. My old 40" Milestars have 42k on them and are pretty worn out.

I found these 42" Baja Boss' on Vision Beadlocks for a good deal. I just put them on today and have put about 60 miles on them. My thoughts so far. They ride great, aren't horribly loud (Yet anyway buy they're still new) My 2015 JK with the stock 3.6 doesn't have any trouble pushing them around. But it does feel a little lazier both in acceleration and braking. Feels like I lost about 20 horsepower or so. For street driving it barely hits the back of the front wheel wells when turning all the way to lock. I will definitely need to attack it with the sawzall before I hit the trails. I havent flexed it yet but I will need to trim the front of the front wheel well also. The rears are good, I cut them the same radius as the Poison Spyder flare plate a while ago, and they look like they'll be good.

It's a work in progress, I'll post more as I begin cutting and tuning. It's going to be a challenge, but not as bad as I anticipated. Here are some pics.

42-3.jpg42-4.jpg42-5.jpg
42-1.jpg42-2.jpg
 
WINspeed said:
Not to bring up an old thread, but I lost my mind and decided to try some 42's. My old 40" Milestars have 42k on them and are pretty worn out.

I found these 42" Baja Boss' on Vision Beadlocks for a good deal. I just put them on today and have put about 60 miles on them. My thoughts so far. They ride great, aren't horribly loud (Yet anyway buy they're still new) My 2015 JK with the stock 3.6 doesn't have any trouble pushing them around. But it does feel a little lazier both in acceleration and braking. Feels like I lost about 20 horsepower or so. For street driving it barely hits the back of the front wheel wells when turning all the way to lock. I will definitely need to attack it with the sawzall before I hit the trails. I havent flexed it yet but I will need to trim the front of the front wheel well also. The rears are good, I cut them the same radius as the Poison Spyder flare plate a while ago, and they look like they'll be good.

It's a work in progress, I'll post more as I begin cutting and tuning. It's going to be a challenge, but not as bad as I anticipated. Here are some pics.

View attachment 411595View attachment 411596View attachment 411597
View attachment 411593View attachment 411594
Click to expand...

Looks pretty mean. Nice. Wish I had tons and 40s.

At this point i am on track to grenade my Pentastar and buy an 8 banger before I can afford tons.
 
You must log in or register to reply here.
Top Bottom