Tire load rating question

[BAYOU]

I am looking to put new Toyo Open Country's on my rig, and they are available in (P) and in an (LT) the LT is a E rated 10 ply, and is 7.5 Lbs heavier than the P rated tire. This is my first 4runner, but I had 4 Tacomas before it that I ran E rated Open Countries on. I am leaning towards the "E" which has deeper tread and stiffer side wall, but I worry that it will stiffen up the ride too much. What do ya'll think? Thanks in advance. :cheers:

 

[Ryan_S]

Get the LT.

 

[Titanpat57]

Get the LT.

^^^ I agree...

 

[Jtraskell]

If those are your only choices, P vs E, then get the E. Unless you are rock climbing or hauling a lot of cement in you rig, E is a bit overkill, but I would rather have overkill then not enough when it comes time to do whatever needs to be done with my rig.....be safe.

 

[BAYOU]

Thanks I am going with the "E" rather have the longer tread life as well. :driving:

 

[Titanpat57]

Thanks I am going with the "E" rather have the longer tread life as well. :driving:

I have 36,000 on my LT Revo's....and they look brand new. I think it'll be worth the safety factor you gain.

 

[Ukie]

Thanks I am going with the "E" rather have the longer tread life as well. :driving:

Remember about a MPG drop. If you do a math, you can probably buy another set of P-rated tires in an expense of an extra $ you'll spend on a gas in a lifespan of LT tires.
Anyway, if your application needs LT tires, go for it!
If you getting LT tires just for looks and can justify an mpg drop, go for it!

 

[BAYOU]

How much of a drop in MPG do you think 7.5 Lbs / tire would be, the P rated are 39 Lbs (which I believe is what the Dumb-lops are) and the LT's are 46.5 Lbs. but the LT's have deeper tread, but again I do not want the ride to be like driving a bouncy ball?:lookout:

 

[JB.]

I am looking to put new Toyo Open Country's on my rig, and they are available in (P) and in an (LT) the LT is a E rated 10 ply, and is 7.5 Lbs heavier than the P rated tire. I am leaning towards the "E" which has deeper tread and stiffer side wall, but I worry that it will stiffen up the ride too much. What do ya'll think?

They'll be a bit more stiff, but when you consider the extra air pressure that should be run in them (compared to P) the combination will be very noticeable.

You didn't say how the tires will be used. Ps generally outperform LTs on pavement.

 

[brockeverly]

Smiles per gallon > miles per gallon. Get the LT Duratracs :trophy:

 

[scanny]

How much of a drop in MPG do you think 7.5 Lbs / tire would be, the P rated are 39 Lbs (which I believe is what the Dumb-lops are) and the LT's are 46.5 Lbs. but the LT's have deeper tread, but again I do not want the ride to be like driving a bouncy ball?:lookout:

It's hard to say because mpg depends on winter/summer gas and driving pattern, I think I my mileage dropped for about 0.5 mpg when I changed stock tire to LT C load. But it might be because I got new tires in October and winter gas kicked in and then there was not much show so I din't go skiing (highway driving) as much as the year before.

 

[BAYOU]

They'll be a bit more stiff, but when you consider the extra air pressure that should be run in them (compared to P) the combination will be very noticeable.

You didn't say how the tires will be used. Ps generally outperform LTs on pavement.

Mostly on road, but lot's of snow and sand driving, I thought the stiffer tire would handle running at very low pressure in the sand better? I didn't think that 7 lbs would effect it too much, where 1Engineer when I need him:shrug: Thanks forum!

 

[Michigander]

Mostly on road, but lot's of snow and sand driving, I thought the stiffer tire would handle running at very low pressure in the sand better? I didn't think that 7 lbs would effect it too much, where 1Engineer when I need him:shrug: Thanks forum!

I put on LT275/70/R17 BFG AT (Load Range E), BFG says they are 32.2" diameter and 55lbs. I am running the tires between 40-45psi.

My mileage dropped by 1 mpg if I watch how I drive, very conservative, mostly around town.

The truck feels much more planted now compared to the stock tires. To me, the stock tires were down right scary on the freeway with a very mushy feel and slow steering response.

The truck actually feels less bouncy with the new tires, most likely has to do with increased un-sprung weight and stiffer carcass.

With acceleration and throttle input, I can definitely tell the difference with larger and heavier tires.

I couldn't wait to get the stock tires off the truck!

 

[desertred]

I'm guessing that you will drop a couple of mpg with an increase of 7.5 lbs per corner. I just swapped the Toyo Open Country A/Ts on my Jeep XJ (wore 'em out) with some Michelin LTX MS2. I had to bump up to a 235 (vs. 225) and a LT tire to get the Michelins. They are 5 lbs heavier than the 225 (P metric) they replaced. I dropped about 1.5 mpg with the switch and could really feel the extra weight of each tire. The 5th gen may be big enough (twice the weight) that the weight difference may not be noticeable. Just another data point.

 

[JB.]

Mostly on road, but lot's of snow and sand driving, I thought the stiffer tire would handle running at very low pressure in the sand better? I didn't think that 7 lbs would effect it too much, where 1Engineer when I need him:shrug: Thanks forum!

Since speeds in sand are very low, it doesn't really matter either way but if someone did a whole lot of it, the P sidewall would last longer as it handles flexing better.

This is based on an answer from <a href="http://www.toyota-4runner.org/general-discussions/110300-ask-tire-engineer.html" target="_blank">this</a> tire engineer but I don't have the reference handy. See the answer from 4/4/2012 at <a href="http://en.allexperts.com/q/Tires-2359/" target="_blank">this</a> link for something recent.

The main operational advantage of LT in a truck the size of a 4Runner is standing up to very rough use off-road (sharp rocks etc). There can be some other minor advantages but in most cases, not nearly enough to offset the many on-road tradeoffs.

 

[Titanpat57]

There's some good reading in there JB..but all I can is the changing over to a LT was the single most significant mod I did on the truck...as the the feeling of "riding on a ball" is described many times with the OEM tires.

It all but disappeared with the LT. I tow, so I do like that little extra confidence. I aloso rode on air downed tires last month fro 3 days at OEX training, and looking at some of the obstacles and rocks...I wish I could say I felt 100%..but at the end of the day, was glad to have the extra protection.

 

[1engineer]

Mostly on road, but lot's of snow and sand driving, I thought the stiffer tire would handle running at very low pressure in the sand better? I didn't think that 7 lbs would effect it too much, where 1Engineer when I need him:shrug: Thanks forum!

These guys are doing fine! Sorry I have been working. Any unsprung weight added, especially during city driving, will be detrimental to fuel efficiency. Remember during city driving you have to accelerate those tires from zero to 400 RPM or so at every stoplight. Heavier tires requires more HP. My guess would be from .5 mpg on highway to 2 mpg city.

 

[BAYOU]

These guys are doing fine! Sorry I have been working. Any unsprung weight added, especially during city driving, will be detrimental to fuel efficiency. Remember during city driving you have to accelerate those tires from zero to 400 RPM or so at every stoplight. Heavier tires requires more HP. My guess would be from .5 mpg on highway to 2 mpg city.

Does an E rated tire last longer than a P? they seem to mostly have deeper tread, and to me that would seem to extend the life of the tire especially with a lighter truck sitting on them. Thanks for the advice. :cheers:

 

[JB.]

There's some good reading in there JB..but all I can is the changing over to a LT was the single most significant mod I did on the truck...as the the feeling of "riding on a ball" is described many times with the OEM tires.

It all but disappeared with the LT. I tow, so I do like that little extra confidence. I aloso rode on air downed tires last month fro 3 days at OEX training, and looking at some of the obstacles and rocks...I wish I could say I felt 100%..but at the end of the day, was glad to have the extra protection.

I can see why you run LTs - I run them myself - but I think it's good to know what the tradeoffs are.

It seems OEMs try so hard to achieve good rolling resistance (they set the specs) that many buyers end up unhappy with the stock tires.

 

[JB.]

Does an E rated tire last longer than a P? they seem to mostly have deeper tread, and to me that would seem to extend the life of the tire...

Because of the depth they often do, but whether they do per dollar is another question. Often, any mileage warranty applies only to the P version.