Developing a HATE for my Load Range E Tires

[Bikeric]

I run 37" D rated Cooper SST Pro's on my Bronco and those things are stiff. I try to keep those at 32psi when warm. I can air those down to 15psi and you can barely tell, hardly no noticeable squish to them.

Oh No!! I'm doing up a set of Cooper Discoverer STT Pro's in 37x13.50R17" with true beadlocks for the Moab Safari. I assumed they would be softer than my Interco Swampers. I run the Interco's at 15psi on the street.

Sponsored

 

[Copperhorse73]

I have 37” load range E Maxxis RAZR and I have to be at 31 front, 28 rear to Pass the chalk test. It’s a pretty comfortable ride at that psi

 

[mcinfantry]

I have been running 40 psi. I wasn't comfortable any less. 32psi? Seems really low but at this point, it is give it a shot or shell out $1500 for new rubber...

Wow

40 is crazy high

I run 32/34

 

[Raptor911]

Yes! Most people don't account for when their tires warm-up from driving or just even sitting in the sun after a cold night. Cold tire pressure goes away quick once they warm up.

I was running 45/46 when warmed up, and that is in winter! When I aired down, you could feel the warm air escaping the valve.

 

[NinjahGoose]

I have E rated Terra Grappler G2's on my 4Runner. I run 45 psi on-road and 20 psi off-road. I used to run 30 psi on-road like Toyota recommends but the gas mileage hit was horrible, now at 45 psi the mileage is much better and the road noise is lower. Keep in mind, these tires are rated to go up to 80 psi, 45 is nothing for them.

*edit* I forgot to add that the tires load rating is based on the max psi of 80.

 

[kodiakisland]

Can't stress enough how valuable an inflation table like this is worth:
Application of Load Inflation Tables Version 2020-7 (toyotires.com)


Assuming those are 35X12.50s, your 40psi is good for a vehicle weighing 6500lbs. If you aren't rolling anywhere near that weight, you need to go down. 30psi is for around 5400lbs. I'd definitely not be running those tires at 40psi.

 

[dankeller13]

Read how to do a chalk test. This will help determine how much PSI you actually need. The placard in the Bronco showing tire PSI does not know you have different tires.

We run 29 front cold PSI, 28 rear cold PSI and our tires tread is touching the road perfectly.

Air gauge and chalk coming out tonight. Thanks for all the advice!

 

[Bonz50]

you dont need E tires unless you're towing some bigger weight or using some huge amount of payload, neither of which are in the bronco's wheelhouse. JMHO

 

[kodiakisland]

you dont need E tires unless you're towing some bigger weight or using some huge amount of payload, neither of which are in the bronco's wheelhouse. JMHO

We run Es for the thicker/stronger sidewalls offroad when aired down, not for payload. Everything is a tradeoff.

 

[BlueBronco]

Oh No!! I'm doing up a set of Cooper Discoverer STT Pro's in 37x13.50R17" with true beadlocks for the Moab Safari. I assumed they would be softer than my Interco Swampers. I run the Interco's at 15psi on the street.

I believe the wider 37's are E rated too...

you dont need E tires unless you're towing some bigger weight or using some huge amount of payload, neither of which are in the bronco's wheelhouse. JMHO

The majority of 35" and larger tires only come in E ratings (some D but very very few C).

 

[B Miller]

I run the new hybrid "D" rated tires from Toyo. Open Country R/T Trails. They are wonderful on the bronco and seem to ride and drive better that the factory tires. They have a reinforced side wall and much less lean during cornering. 37 psi cold. I'd buy these again in a heartbeat!
https://www.toyotires.com/product/open-country-rt-trail/

 

[JediMcMuffin]

Can't stress enough how valuable an inflation table like this is worth:
Application of Load Inflation Tables Version 2020-7 (toyotires.com)


Assuming those are 35X12.50s, your 40psi is good for a vehicle weighing 6500lbs. If you aren't rolling anywhere near that weight, you need to go down. 30psi is for around 5400lbs. I'd definitely not be running those tires at 40psi.

That link is GOLD.

 

[Boreal]

I’m on OEM KO2’s (C range). 40psi was way too much pressure, to maximize the contact patch for traction and maintain healthy wear I’ve found 32/31psi Cold to be the winner. You should have zero fear with running 30-35psi daily. Even high twenties would be fine, IMO. In the winter mornings I often see 27psi or so on the TPMS readout… I still say that ford should offer a setting within sync that allows us to set the TPMS range to fit our desire.

As Kodiak said, the E range must be for tougher carcass/sidewalls… otherwise, you are just paying more for a rougher ride… if you are set on the rubber, drop the pressure; it should wear better too

 

[ramblinwreck]

I have been running 40 psi. I wasn't comfortable any less. 32psi? Seems really low but at this point, it is give it a shot or shell out $1500 for new rubber...

40 PSI is crazy high for a 12.5” wide tire. On my BFG KM2s on my Rubicon I ran 28 PSI and it passed the chalk test just fine. I run 32 in my Sasquatch Bronco and I think that is on the high end of what I should be running.

 

[diggs44060]

I run my bfg km3's E..
Badlands Sasquatch 2Door(35×12.5×17)
At 30-32psi and deflate to 15-16psi off roading

Sponsored