Before I begin, I'd like to apologies if this question may have been asked on an older thread. I just swapped out my old 235/55 Bridgestone Ecopias for 255/50 Michelin CrossClimate 2's. I know that the recommended tire pressure for the RX is around 34psi but with the slightly thinner sidewall, could it be assumed that pressure should be raised by approximately 2-3psi more? Also, what kind of impact to mileage has anybody here seen in running wider tires?

Would love to hear any feedback!

 

Here is a handy tire pressure calculator that might help you out:

https://tirepressure.com/255-50r20-tire-pressure

 

I have put larger tires on many vehicles. Not on an RX, but probably the same result...

I found a few extra pounds is needed so the tire doesn't feel "loose" on the road. But your profile is lower so...Trial and error till you get the feel you like.

As for gas mileage, probably less.

I think the big change will be getting rid of the Ecopias.

Cheers

 

You're actually going to have a double or triple hit as you are also switching from an eco tire with low tread to a 3pmsf tire with full tread, not just the width.

For winter tires it is often recommended to increase tire pressure by 3-5
​​​​psi to make up for the softer rubber; for a all weather tire like the cc2 you could take half the recommendation and so you need an additional +2psi as well (on top of the width adjustment). If you want to throw on another one for full tread that's logical and up to you too.
This puts an adjusted starting point like at 39 and +6 over the door.

Aso far as what is proper psi you can go down several rabbitholes on this and there are several schools of thought. Go read some other threads if you want your brain to melt. Personally I think several psi higher inflation is solely a tradeoff only for comfort, there are no performance downsides with several psi higher assuming you're still well under the max inflation.

​​​​With modern premium tires, the old mechanics tale about overinflation causing excessive center wear just does not happen in the properly rated tire.. It is always better to be a little over than under especially if you don't check your tires to often.

You'll see in the book is if you do high speed driving (on high performance tires) you are instructed to increase psi by like +5 to +11 psi. If your tires turned into round balloons when overinflated this would not be in the manual.

Ultimately try for yourself. Do use your own pressure gauge and not just the tpms, even a cheap $2 one. If ride is too rough for you when hitting bumps or whatnot, drop your psi.

Also remember for new tires, you may need to wear in at least 500miles for the tire to wear off any factory nubs/oils and the tread matches your alignment before coming to any conclusions.







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This is great, thank you!

 

Not that I had anything against the Ecopia's, I just thought its very limited tread life was just an absolute turn-off. As if the cost of tires is enough, I was at my local tire center when he asked for my wheel lock. I opened the hatch and looked under the cargo floor only to find it missing. Somehow Lexus down in Florida found it convenient to take and not return it when I had two of my Ecopia's swapped due to un-patchable nail punctures. So, another 75 dollars down the drain though I really appreciated the dealer not charging me labor to have them swapped out. I was told that every dealer should have several sets of master locks so to why they used mine was absolutely beyond me.

 

Really appreciate you taking time out for the lengthy response and I too am in the school of over-inflating my tires by 2-3 psi. In fact, the tire store seemed to do exactly this at 37-38psi so I'll just start there and try to re-adjust if necessary.

Does anybody here have any experience with the CC2's?

 

That placard states 33 psi. However, you adjust accordingly to your liking.

I usually like to add +2 psi over the placard's recommendation.