Tires: Correct Pressure fo E-Range tires, goodyear wrangler, bridgestone tires

Question
Hello,

I have a 2010 Toyota 4Runner with a curb weight of 4,750 lbs.  I recently upgrade from my cheap OE Bridgestone H/T tires (C Range) to a new set of Goodyear Wrangler DuraTracs (E Range) of the same stock size: 265/70/17

These tires will be offroaded on a monthly basis (trails, rocks, creeks, sand, etc...) but most of their time will be spent on road.  They will see occasional towing.

I've had people tell me that E Load tires require a higher air pressure thean C Load tires.  But a the same time I called Goodyear and they recommened I run the stock pressure in the (32psi).

What pressure do you recommend I run for safety, performance and tire longevity.

And how low is too low to air down for sand and rocks?

Thanks a million!

~ Ryan

Answer
Ryan,

I can only partially answer your question - and I'll explain why.

First, Load Rand E (and any tire that is designated by "Load Ranges") are "LT" type tires - and those letters will appear before the numbers in the tire size.  They are important - and you'll see why in a moment.

Your vehicle came with "P" type tires - and those letters will appear in front of the tire size as well.  If you do the math "LT" type tires require around 15 psi more than "P" type tires with the same numbers.  So look closely at the vehicle tire placard to verify that the original tire size (the ones from the factory) it will have the letter "P" in front of the size.

The info on 2010 models gets published this month, so I am not up-to-date, but the info I have on 2009 models lines up with everything you said - except that the Bridgestone tires are Load Range "C" - and I don't think they were.  I think there were Standard Load P metric tires.  But it is possible that the dealer switched tires.

Nevertheless, the Goodyears are going to need more pressure - and I did the exact calculation and it's 44 psi - which is why I do not recommend replacing LT tires for P metrics.

But this is the "on Street" value.  "Off Road" is a whole different animal and depends very much on the terrain and the speed - and experience is a great teacher here - and I have no experience in this area.  So I can not in good conscience give you a value.