jmhenrie

when I picked up my 450h last November all the tires were set at 33 psi, and my best highway mileage was 27.2 mpg, went in for the 6 month/5k service, got halfway home and check the tire pressure 38-39 psi, checked them cold this morning and all at 38 psi. the good news I averaged 29.9 mpg for the 150 mile trip home. rides the same on the highway but defently stiffer on bumpy roads. so is 38 psi to high, sticker says 33.
19 inch dunlopes.
thanks mike

Cruiter

32/33 is where I keep mine too. As per the door sticker. Every ones driving style and conditions are different but that should give you the best combination of handling, mileage, and maximum tire wear. Harder tires will give you better mileage but require new tires much sooner. Your choice. My average for nearly four years has been a tick over 30mpg average.

markrivers

34 on all 4s.
As long as you don't go over what's printed on your tire ( not on the door), your tires will be ok.

BertL

38 when cold on my 19" Bridgestones.

Per a previous thread where ome of this was discussed, my dealer sets them at 38-40 nowadays. I rode with a lower PSI after initial delivery, but kept raising it over a number of weeks and have stayed with 38 for several months now. I agree it's a little stiffer, and a bit more jarring if I take parking lot bumps too quickly, but otherwise, prefer my ride this way.

corradoMR2

32 to 33 psi all around, and never higher than 34.

When the dealer sets it to about 37-38 psi, the F-Sport rides the fine line of being stiff and on the harsh side and I have Michelins (is this the psi all those journalists test the F-Sport shod with Dunlops?)

MjThind

Mine is at 32 nice and smooth...

ecr72

I can't find anything to support this. I used to run a set of Goodyear TripleTreds on my Jetta at 45-50 psi in the summer to maximize my MPG (35-40 in the winter) and I got 60K out of those. I can't imagin my overinflation caused them to wear out much sooner than if I ran them at 30-35 all the time.

On our RX, we're running our Michelins at 38 psi. I'd rather a "low" tire be around the mfg recommendation than well below it.



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Cruiter

My (h) recommendation in the door jam is 32psi all around. And that gives me an average of a tick over 30mpg constantly. Hard to beat in this car.

ecr72

I don't doubt that. I'm just curious if higher pressure does indeed reduce tire life. I thoght it was the opposite. Now I'm confused wondering if what you say is correct.


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jclem

I've always compromised between car door jamb label rec and tire rec. Thus splitting the difference between cushiest ride and higher mpg/longest tire life. So I set them at 40.

Cruiter

RE: OEM street tires, the door jam recommendations are what the vehicle manufacturer has determined will offer the best combination of handling, comfort, mpg, and tire life. If you add say 4lb of air, you're going to get a little harsher ride and maybe a little more cornering ability before traction is lost and less tire friction which will give slightly more mpg. The downside is more stress on the belts and the center of the tire will wear faster as higher pressure is making the center the primary contact patch (try to imagine just how much stress those belts are taking as you take a corner in a 4500lb car at speed and change it's direction). If you have two little air, then you loose some cornering ability, less mpg (more friction from softer tire), and edge of tire wear, maybe even cupping. There's always a sweet spot, choose wisely as these tires aren't cheap.

Dolphin

As a result of this thread, this morning I lowered my pressure from 40 to 34, which is still two over the 32 suggested.... huge difference, much nicer ride... removes the tiny road imperfections from transferring through to seat. 19" wheels... those with smaller rims can prob. get away with slightly higher pressure and still absorb road imperfections...

wilchan

I set 33psi on all four. 19" with Dunlop. 2013 RX350 AWD.

I found car gets bouncier at 34psi and ride gets harsher at between 31-32psi (weird.) So 33psi seems to be the sweet spot at the moment.

ecr72

Wow. I've never tried, but I doubt I'd be able to tell the difference in 1 or 2 psi.

I may try decreasing them to what Lexus has on the sticker and do an A/B comparo but that will be 6 psi I believe.


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BarrettF77

Dealer evidently had mine at 22lbs. Set it at 35 each. I'm happy with that, will give it a little time at this pressure and see how it does. Given the 700 miles at 22, I'm sure a little more center wear is ok to try it out.