RX400h Posted January 2, 2010 Posted January 2, 2010 As many of you have discovered, the factory-recommended tire pressure for RX400hs has been 30 psi for each tire. (At least it is specified as such for our 2006) Unfortunately, keeping the OEM Goodyear tires pressurized to this number often resulted in excessive wearing of the inner and outer tread areas, indicating that 30 psi was just not enough. Upon having Bridgestone Alenzas (factory size) tires installed, I adjusted the air pressure up to 35 psi. Well, that appears to be too high, as I am seeing more wear in the center area of tread than is evident at the inner and outer areas. Thus, I have lowered each tires's pressure to 32 psi. The tires now have over 25,000 miles on them. So, to those of you who are running Alenzas, I recommend no more than 33 psi air pressure. Oh, I forgot to mention that I rotated the tires the other day and was pleasantly surprised that the brake pads looked almost new. The fact that the RX has more than 45,000 miles on it makes it astonishing. The RX330 or 350 owner would have spent over $200 for new pads, quite some time ago, I would assume. Dave 1
SC 300 lover :) Posted January 2, 2010 Posted January 2, 2010 i run my lexus sc300 on either 30psi back and 32psi front or 32 back 34 front.
RX400h Posted January 3, 2010 Author Posted January 3, 2010 What does the door sticker list for your car?
cduluk Posted January 3, 2010 Posted January 3, 2010 Thanks Rx400h! It's good to know, as my next set of tires will probably be the Alenza's. I had the Alenza's on my Rx300 and i loved them. <_<
RX in NC Posted January 3, 2010 Posted January 3, 2010 Hold on there, RX400h. Much depends upon the vehicle, the climate, the driving habits, and the care & feeding that owners provide to their particular tires.... I ran the first set of Alenzas on my wife's 2004 RX330 AWD at 36 to 37 psi year-round to maximize fuel economy as well as treadwear longevity. Rotated them myself at every oil & filter change which I also do myself. They went nearly 58,000 miles before I decided to replace them back in October with another set of Alenzas when she hit a big, nasty bolt in the road and ruined one of her tires as a result. Since they were all down to just over 3/32 of remaining tread and getting just a little noisy (although still safe even in heavy thunderstorms), I replaced the original set and got a nice adjustment from the folks at Discount Tire as well.... Still running the new set of Alenzas at 36 to 37 psi just as before and they're doing fine.... So don't arbitrarily advise folks not to run their tires at greater than 33 psi. You don't know the vehicle, the climate, the driving habits, or the care & feeding that the tires will receive. Some vehicles and situations call for higher pressures. The key is to know what the hell you are doing before you decide your psi strategy in your particular situation....
RX400h Posted January 3, 2010 Author Posted January 3, 2010 RX, I am assuming that someone who drives a much lighter vehicle would know that they shouldn't mimic the tire pressure maintained in tires on a vehicle that weighs quite a bit more. An RX330 is not an RX400h; I guess I have to spell that out before you assume otherwise. Of course, the average tire temperature will also make a difference, but we've driven our RX in 38 degree through 85(F) degree temps which, while not as wide a range as is experienced by some forum members, it is still wide enough for me to recommend that 33 psi is a good starting point. By the way, I maintain each tire's pressure very consistently and am assuming that others know that a 33 psi max recommendation does not mean that 27 - 39 psi would produce the same results. I did add a comment, just in case others are not the least bit knowledgeable about tires.
lemon Posted January 3, 2010 Posted January 3, 2010 I've been running my Michelin MXV4 at 34 psi with good results. Same for my winters - Michelin Pilot Alpin. Also remember that for every 10 degree farenheit drop in temp, you lose about 1 psi. I know lots of people that set their pressures just once - in the summer when it's warm and not as much of a pain to do (compared to checking in freezing temps in the snow when most people don't want to exit the nice climate controlled vehicle). As such, they end up running under pressure for the duration of the winter.
RX400h Posted January 4, 2010 Author Posted January 4, 2010 Certainly, when the ambient temps dip, tire pressure should be checked and adjusted. Setting your pressure to 34 in a garage may mean that the pressure in the tires while driving on a 0 degree day is 30. According to Tire Rack, The rule of thumb is for every 10° Fahrenheit change in air temperature, your tire's inflation pressure will change by about 1 psi (up with higher temperatures and down with lower).
Angus Posted January 19, 2010 Posted January 19, 2010 [...] I adjusted the air pressure up to 35 psi. I'm still on OEM Goodyears (which I can't say that I'm overly impressed with, but the tread is still hanging in there at 19k miles) on my '07 400h. RX400h, can I deduce from your OP that you would still recommend, on the OEMs, 35 psi, just not for the Alenzas?
RX400h Posted January 19, 2010 Author Posted January 19, 2010 I can generally feel whether the outer or middle treads are wearing faster, but other than using a penny to gauge tread depth, a great way to do this accurately is to buy a digital tire depth gauge. MSC industrial supply has a Fowler unit at a reasonable price. What I'm getting at is that if your tires are wearing evenly, there is no reason to change the pressure in each. I am certain, however, that the 30 psi listed on the door jamb sticker is too low, especially for the OEM Goodyears. Dave
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