08-09-2011, 08:42 AM
Question for you all...
I'm driving a Gen-2 Tundra with the 5.7 liter and regularly haul a 24' Travel Trailer as well as small cargo trailers. My Tundra is also my daily driver.
I've recently upgraded from the Bridgestone Dueller that came as the OEM tires on my truck. (275/65r18) I replaced them with a set of Michelin E-Rated tires in the same size.
I know that E-Rated tires can go up to 80psi. My question is; for those of you who use E-Rated tires, what PSI do you keep the tires at between towings?
Just had the oil changed and my stealership rest the pressures down to 35PSI (the pressure that shows on the door). Do you keep them high or do you go up and down as necessary?
08-13-2011, 07:13 PM
I would go with whatever the max pressure is on the tire and see how that feels. Then you can just back off from there to get it where you want it. At 35PSI it must be a little sloppy in the corners.
08-13-2011, 09:39 PM
A good rule of thumb is to start at about 55-60% of the max pressure (unloaded) and see how the contact patch wears (chalk trick). Adjust up or down depending on tire wear, comfort level, etc.
I have D-rated Nitto Terra Grapplers (max pressure: 65psi cold) that I run on my AC at 42psi front/40psi rear.
08-14-2011, 05:30 AM
My rock warrior came with load range E tires 285/70/17..............the door says to run them at 46 psi cold. Currently between towing and have dropped to 65 psi.
After the next time I tow the camper I'm going to drop it to 50 or 55 psi. At 65 psi, it seems to make the steering a bit fast unloaded. Hope this helps....
Oh, and I do not have enough miles on to observe any kind of wear so this has not become a factor yet.
08-20-2011, 05:45 AM
I run mine at 40, but don't do too much hauling or towing anymore...
08-22-2011, 05:13 PM
It's best to consult the manufacturers load-pressure table.
Here's an example: http://www.michelinrvtires.com/michelinrv/report.do?ReportType=LoadAndInflation
If you look at the L-P table for your OEM tires, you'll find the table calls out exactly 1/2 your GAWR (Gross Axle Weight Rating) for the applicable tire.
80 PSI is probably about 3400 lbs per tire capacity for your E-rated tires....great if your axle is rated about 6,800 lbs (and probably pretty good for mileage), but probably not so good for braking/handling and tire wear. Since your rear axle is rated for about 4,000 lbs, you'd only need approximately 2000 lbs per tire. The front would be slightly less due to the lower GAWR. I would shy to guess what that PSI would be for your new tires, though. It's certainly less than max per the sidewall.
If you get the chart from Michelin for the OEM size, please post it here. I couldn't locate it online in my brief search.
More info here:SAFETY | Toyo Tires (http://www.toyojapan.com/tire-technology/safety/)
and here: Michelin North America RV Load & Inflation Tables (http://www.michelinrvtires.com/michelinrv/tires-retreads/load-inflation-tables.jsp)