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Help with new tires for the Ranger


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E rated tires are stiffer.  You can actually run less pressure.  The appropriate amount of tire pressure is the pressure your tire runs with the full contact patch on the ground...ie...all the way across the tire.  

 

Off road the tire can generally be aired down to around 12-15psi and stay on the rim as long as you aren’t hot dogging it with high lateral stress.  (High speed donuts)

 

Example:

Jeep with P rated tires at 35psi stock

lifted plus two tire sizes and E rated tires 26 psi on road

mixed off and on road driving below 50mph 16psi (for weeks at a time)

Airing down for off-road only 10-12 psi


This is the thought process by many dedicated Jeepers with lifted rigs running E rated tires. I

 

i really hate the idiot lights, but I do like the displays that actually tell me what the tire pressure is in the tire.

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To close the loop, after doing some hydroplaning in the rain the other day, plus with winter on the way, I decided to bite the bullet and buy the new tires now even though the old ones might have last

I have the feature showing me the PSI in all four tires on the new to me Tacoma. It’s a cool deal, but you can become neurotic about checking it all the time...almost as obsessive as checking your MPG

Read this article as well.     https://www.outdoorlife.com/story/hunting/how-to-build-the-ultimate-hunting-truck/   He chose your truck by the way    the part about tires

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23 minutes ago, Windrider said:

 

 

i really hate the idiot lights, but I do like the displays that actually tell me what the tire pressure is in the tire.

Agree.  My wife's toyota avalon will throw a code when there is low air pressure.  But won't tell you which tire, or how low it is.  The last time we let it go to long and it had to be cleared by a mechanic.  Ugh.  Useless.  

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9 hours ago, Greg Hartman said:

 

Not a silly question at all.  I am running them at 45 psi, because that's what the tire shop recommended.  The OEM door sticker on the truck says tires should be 33 psi

 

The combined level of knowledge here on almost any subject - except women, I suspect  🙂 - is nothing less than amazing.  Thanks to all who took their time to share their expertise!

 

Dumb question - does the effective load rating matter if you are not hauling weight at a given moment?

 

From the sound of the expert advice here, I decided to bump the new tires up to 60 psi first thing tomorrow.  I will call Goodyear and inquire, as well.

 

FWIW (and this is just based on my personal experience), I believe that I get better sharp rock puncture resistance when running at lower pressures - maybe 35 psi or so.

 

Here's another question.  We spend a month or two each spring camping on the island of Orkacoke in the Outer Banks (can only get there by boat).  We do a lot of sailing among the islands, but we also drive way out on the empty beaches for a while most nice days and set up a little beach camp to run the dogs, surf fish and watch the sea.

 

5-9-19 - Joy on the beach

 

5-23-19 - Beach camp

 

Hopefully the COVID wont prevent us from getting down there again this spring.

 

The sand is soft and it's easy to get stuck up to the frame, even in a 4x4.  The place is pretty remote and there is not a lot of quickly available help if you do get stuck.  I've seen more than one nice truck stuck in the sand that was swallowed up when the tide came in.  Normally, I run my tires at about 20 psi and try to sort of "float" on top of the sand.  What do you recommend with these new tires?  Might they come off the rims at such a low pressure?  Will the aggressive tread be a problem and tend to dig in more than float over the sand?

 

I am with the same woman after nearly 46 years but that does not qualify me to comment.

 

Your tire choice is what I use.

 

Perk

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8 hours ago, Greg Hartman said:

 

 

From the sound of the expert advice here, I decided to bump the new tires up to 60 psi first thing tomorrow.  I will call Goodyear and inquire, as well.

 

 

 

Whoa Greg, hold off on doing that! Sorry.  I didn't mean for you to take me using your example so literally. I was using approximations to illustrate the point. The load rating of a tire is proportional to the pressure, but it is not perfectly linear like I used in my simple math example in which I happened to use your tire size. 

 

Definitely call the tire manufacturer to verify all of this....

 

but out of curiosity I actually went ahead and looked up the actual load vs pressure ratings for your tire size:

 

LT265/65/17 E load

35psi = 1765lbs

40psi = 1935lbs

45psi = 2105lbs

50psi= 2270lbs

55psi= 2420lbs

80psi = 3085lbs

 

P265/65/17 

32psi = 2260lbs

35psi = 2337lbs 

 

So basically your stock rating at 33psi on a P-series tire is 2,300lbs but there is a weird "rule" in which P series tires when used on light trucks gets de-rated by 9% so your actual rating is basically 2,100lbs. So when looking at the load vs pressure ratings of an E series tire, your tire shop was right on the money at 45psi! 

 

On the sand question I have not first hand knowledge.

On the 20psi front I can say anecdotally that I have used and seen in use E-series tires at 20psi and even a bit less in slow off road usage with no issues with the tires coming off the bead. 

 

Just as an FYI and something I honestly wasn't sure so googled it, but the only "official" recommendation I could find regarding minimum recommended pressure for a E load tires was a note from "JATMA" that recommends no less than 58% of max pressure rating ie .58 X 80psi = 46psi. That would be for on-road usage and I personally would have no concerns going to 20psi for beach usage but it does illustrate that 45psi would the lowest you would want to go on your new tires for normal road usage. 

 

The main point I was trying to make earlier was that many people think because the are going to a heavier load tire they can run at lower pressure than the stock tire, when the opposite is actually true. I probably should not have used your size as an example with such rough math not realizing you would run with those numbers. Again, double check with the manufacturer but I believe you are right where you want to be at 45-46psi in your new tires. 

 

 

Here is some info for those that may be curious.

 

general tire load info with 9% derating for Ptires on trucks

 

detailed tiring ratings with load vs pressure charts

 

reference with min pressure being 58% of max for E load tires per JATMA

 

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12 hours ago, dogrunner said:

But they should also go up a bit as you drive and the tires heat back up. I’ve never had mine drop that much but I could see it happen. 

 

Yes, they go up as you drive. With the camper on they'll climb well into the 90s in the summer. Like I said, I watch it like a hawk and adjust as needed.

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I have the feature showing me the PSI in all four tires on the new to me Tacoma. It’s a cool deal, but you can become neurotic about checking it all the time...almost as obsessive as checking your MPG...

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2 hours ago, Brad Eden said:

I have the feature showing me the PSI in all four tires on the new to me Tacoma. It’s a cool deal, but you can become neurotic about checking it all the time...almost as obsessive as checking your MPG...

 

My new truck has that feature - not having bought a new vehicle in many years, I'm boggled (obsessed?) with all of this.  I actually find that if one side of the truck is facing a bright sun, the tire pressures on that side can be a tiny bit higher.  🙂

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10 hours ago, Flush said:

 

Whoa Greg, hold off on doing that! Sorry.  I didn't mean for you to take me using your example so literally. I was using approximations to illustrate the point. The load rating of a tire is proportional to the pressure, but it is not perfectly linear like I used in my simple math example in which I happened to use your tire size. 

 

Definitely call the tire manufacturer to verify all of this....

 

but out of curiosity I actually went ahead and looked up the actual load vs pressure ratings for your tire size:

 

LT265/65/17 E load

35psi = 1765lbs

40psi = 1935lbs

45psi = 2105lbs

50psi= 2270lbs

55psi= 2420lbs

80psi = 3085lbs

 

P265/65/17 

32psi = 2260lbs

35psi = 2337lbs 

 

So basically your stock rating at 33psi on a P-series tire is 2,300lbs but there is a weird "rule" in which P series tires when used on light trucks gets de-rated by 9% so your actual rating is basically 2,100lbs. So when looking at the load vs pressure ratings of an E series tire, your tire shop was right on the money at 45psi! 

 

On the sand question I have not first hand knowledge.

On the 20psi front I can say anecdotally that I have used and seen in use E-series tires at 20psi and even a bit less in slow off road usage with no issues with the tires coming off the bead. 

 

Just as an FYI and something I honestly wasn't sure so googled it, but the only "official" recommendation I could find regarding minimum recommended pressure for a E load tires was a note from "JATMA" that recommends no less than 58% of max pressure rating ie .58 X 80psi = 46psi. That would be for on-road usage and I personally would have no concerns going to 20psi for beach usage but it does illustrate that 45psi would the lowest you would want to go on your new tires for normal road usage. 

 

The main point I was trying to make earlier was that many people think because the are going to a heavier load tire they can run at lower pressure than the stock tire, when the opposite is actually true. I probably should not have used your size as an example with such rough math not realizing you would run with those numbers. Again, double check with the manufacturer but I believe you are right where you want to be at 45-46psi in your new tires. 

 

 

Here is some info for those that may be curious.

 

general tire load info with 9% derating for Ptires on trucks

 

detailed tiring ratings with load vs pressure charts

 

reference with min pressure being 58% of max for E load tires per JATMA

 

 

 

Wow!  Thank you again, Flush, for taking all of your time to do this.  I guess there's nothing else to do where you live, since there are no birds out there and you recommend that everyone travel here to PA to hunt.  🙂

 

I talked to BF Goodrich today.  Took forever on the phone, but here's the "official" word on psi: 

 

For normal, everyday use, for my truck with my tires, they recommend 40 psi.

 

For rough, off-road use they recommend airing down 3-6 psi.  They say that this will allow the tire to flex more and thereby be less likely to be pierced by rocks.  That has been my real world experience, too.

 

For soft sand beach use, they say that the tires should not be aired-down to any less than 26 psi (when cold!) or there can be a risk of dismounting the tire.  They also were very clear that the tire must be re-inflated to 40 psi before any road driving at all.  FWIW, being a lawyer, I felt I was hearing "lawyer-speak" here.  In other words, I think this is likely a vey conservative number for fear of liability if people go out on the road and drive at 70 mph with tires at less than 26 psi cold.  In my experience, you can safely drive a Jeep with 20 psi tires on the road as long as you don't go over, say, 25 mph or make any violent maneuvers.

 

For max load capacity, they recommend 80 psi, which gives a load rating of 3,085 lbs/tire.

 

So, here's my plan:  I'm gonna go with 40 psi for normal use.  If I carry any heavy loads, I'll air up to 80 psi.  I'll air down to 30-35 psi for nasty western off-road next fall.  I'll give 26 psi a try on the beach in the spring, but if I start to dig in, rather than float over, the sand, I'll just stop and air the tires down to 20 psi as usual, but be very careful not to drive at any speed or to do anything that could apply lateral force to the tires.

 

Thanks again to everyone!

 

A road made of sharp scree rock in grizzly country:

 

10-5-20 - An interesting road

 

10-5-20 - Grizzly country - 2

 

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1 hour ago, Greg Hartman said:

They also were very clear that the tire must be re-inflated to 40 psi before any road driving at all.

Greg, I think this has some truth to it.  I had a slow leak flat last summer a ways off the pavement and as luck had it the spare was also low.  I ended up finding some folks that had a compressor (as I do now as well....lesson learned) but I had to drive a few miles on the half flat tire on a county gravel road.  When I took the tire into the shop to get a patch on it they said I had driven on it too far and the inside of the sidewall had deteriorated.  They showed me the rubber "dust" inside the tire from the sidewall.  That was a new one to me but I've known the guy who owns this tire place for a few decades so I trust what he has to say.

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5 hours ago, Brad Eden said:

I have the feature showing me the PSI in all four tires on the new to me Tacoma. It’s a cool deal, but you can become neurotic about checking it all the time...almost as obsessive as checking your MPG...

 

I know what you mean. I have the tire pressure monitor set as the second default on the instrument panel in my truck.

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4 hours ago, Greg Hartman said:

 

 

Wow!  Thank you again, Flush, for taking all of your time to do this.  I guess there's nothing else to do where you live, since there are no birds out there and you recommend that everyone travel here to PA to hunt.  🙂

 

 

 

You're welcome. I'm just trying to win over a friend so I have a local contact when I make my trek to the bird-hunting nirvana land of PA!

 

Glad you got through to BFGoodrich and they gave you the official scoop. I'm slightly surprised they recommended less than 46psi because I know some manufacturers follow the JATMA guidelines and won't go below that, but it's really not that big of a deal and the difference between 40 and 46 isn't that significant of a difference.

 

I'm also confident you will be fine 20psi as long as you don't go fast and crazy. 

 

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10 hours ago, Brad Eden said:

I have the feature showing me the PSI in all four tires on the new to me Tacoma. It’s a cool deal, but you can become neurotic about checking it all the time...almost as obsessive as checking your MPG...

 

I looked around inside a Ram truck with the Warlock trim, the supposed basic version, and the 4 PSI numbers were right there in the dash display.  I told the guy I'd rather not have all of the electronics, even hand cranked windows would be fine but that's no longer part of the deal.

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