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Discussion Starter #1
Just had some Hankook DynaPro MT 265/70 r17 installed yesterday and noticed the shop inflated them to 35 lbs. They read the PSI on the drivers door which was for the OEM tires.

These tires can handle 80 lbs.
@ 35 lbs, the XK is a little sluggish but the ride is very smooth.

Which PSI do you guys recommend?
 

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Per the TRA load vs inflation tables, 35-40 psi is a good range. Anything over 40 psi is overkill (though if you're towing max capacity it couldn't hurt to bump up to 45-50 for some extra sway stability)

Id run those tires at 35 psi cold inflation.
 

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Discussion Starter #4
Very helpful... thanks guys!
 

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Higher PSI will give better gas milage, better cornering, more towing/payload capacity and a harsher ride.

Lower PSI will give worse gas milage, worse cornering, less towing/payload capacity and a smoother ride.

As tire size goes up, PSI can generally go down as you have more square inches supporting the same vehicle weight and therefore need less pressure/square inch. This will give a smoother ride as the softer tire will absorb the terrain and not transmit it to the cabin, however, the above mentioned cons will come into play.

Generally speaking, if you aren't driving like a nut and/or trying to squeeze every last penny out of the gas mileage (two opposite extreems) less pressure is more comfortable for regular driving.
 

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too high of psi will give you worse cornering, longer braking distance, and less maneuverability in an emergency swerve condition due to lack of contact area with the ground (only riding on the center tread).

When it comes to tires, the "proper" psi is best. Both under-pressure and over-pressure have major downflaws.
 

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Rule of thumb for the correct starting pressure is when the tyre pressure has a 3psi increase from cold to hot.
 
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