2018 Mild build help
- Thread starter Mikesvander
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SQRRRL
SILVER Star
Not a hassle at all. Rail hate drops no problem. On this road trip I used the tail gate as a diaper changing table.
Hello @gaijin , would 40PSI be the same recommendation for an LX on the Cooper Discoverer AT3 LT285/70R17 121/118S load range E?
Thanks!
No.
The RCTIP (Recommended Cold Tire Inflation Pressure) for the Cooper Discoverer AT3 LT285/70R17 121/118S load range E tires on your LX570 is 35psi F/R.
HTH
Thanks for the answer Gaijin. Just curious why the psi would be different for the LC and LX when the tire is the same (unless I'm misreading the post)? I realize that the stock weight of the LX is 180lbs over the LC but didn't think it would make that much of a difference. However, I'm not the expert which is why I'm asking. Not doubting, just curious.
I've posted about the differences many times, but the basic answer is that the LX570 and LC200 suspension systems are tuned for different tire Load Limits.
The LX570 required tire Load Limit is LESS than the LC200 required Load Limit.
For tires of the same size, Load Limit is adjusted by changing the tire pressure.
For ALL LT285/70R17 tires, the RCTIP for the LX570 is 35psi while for the LC200 it is 40psi.
Your question is a good one. As much as I have tried to make the difference in RCTIP for the LX570 and LC200 clear, I fear many are mixing them up. Never hurts to go over it again.
Tire pressure isn't an exact science based on load limits. It's a solid safe start. Tire pressures are further tailored for other considerations including cornering stability, wear, and yes, suspension, etc. And subjective fuzzy things such as ride quality. The reality with suspension tuning is that the moment one changes a tire model, tire size, or anything in between, optimal pressures may very well be different so I personally wouldn't put too much stock in hitting exactly those recommended pressures.
I'd go so far as to say many LCs on these boards subject themselves to unnecessarily high tire pressures when they could just as safely run LX derived pressures.
I'd go so far as to say many LCs on these boards subject themselves to unnecessarily high tire pressures when they could just as safely run LX derived pressures.
I run an oddball tire that isn't on any charts. As best I can tell, the answer to the correct tire pressure is: no lower pressure for road use than heats more than 10% cold to hot. Example: 35 psi cold -> 10% 3.5 PSI -> 40 PSI hot means this tire is at too low a pressure and needs more air in it to control heat. Example: 37 psi cold -> 10% 3.7 psi -> 40 PSI hot means this is an acceptable low end for the pressure.
You can then run more PSI as you want up to the marked limit on the tire to control other factors (load, road conditions, desire for high mpg, cushy feel, mad cornering, etc).
The great thing is when you're reading articles on this they get into the whole tires are built with heat and fall apart with heat, so you'd better control the heat and nothing else matters discussion.
YMMV.
You can then run more PSI as you want up to the marked limit on the tire to control other factors (load, road conditions, desire for high mpg, cushy feel, mad cornering, etc).
The great thing is when you're reading articles on this they get into the whole tires are built with heat and fall apart with heat, so you'd better control the heat and nothing else matters discussion.
YMMV.
I'm curious - what tire is that?
yes, the infamous LT275/80r18. Load 129. Max psi 80. On my rig it feels best around 34-36, but the heat test puts it at 36-38.
You're right - the LT275/80-R18 tire does not exist in any of my reference materials.
Thanks for letting me know. I'll make a note and see if I can find anything and get back to you if I do.
All I can really pass on now is that ALL LT-Rated tires have an absolute minimum cold inflation pressure of 35psi.
HTH