Tires

[verdesardog]

Over on the diesel sites everyone is wishing for BIG E rated tires. Big D rated tires are far better than E's

E tires of the same load rating need more pressure than D's for the same load handling capabilities. The only time you need E rated tires is if you go with small OEM type of tires. Ask your tire shop, they will set you straight.

When I bought tires for my truck I was wishing for E's but the shop showed me the tire load/inflation charts.
For the tires I bought (load index of 121) I need less than 35 psi. With E rated tires I would need 45. If I had an axle load of 6000lbs I could run at 50psi, for E tires you would need 60!

The bottom line is E rated tires will give you a harsher ride than D's because they have to be inflated more for the same load. Will that make them any tougher? Probably not. And you will be able to get a bigger foot print at lower psi too....

Here is part of a load/inflation chart for common E and D tires:

[wingerak92]

So that chart,
These tires would handle 3000lbs over each axle at 50PSI? That's the general idea?
http://www.atturo.com/moto/trail_blade_mt
Load range and speed rating: 119Q 8PR LR D

[verdesardog]

opps, see below LOL

[verdesardog]

So that chart,
These tires would handle 3000lbs over each axle at 50PSI? That's the general idea?
http://www.atturo.com/moto/trail_blade_mt
Load range and speed rating: 119Q 8PR LR D

no, 3000 for each tire so 6000lbs per axle.

I asked the guys at discout tires for a chart for my specific tires and was told that all tires go by the same chart according to the load rating marked on the side walls.

[wingerak92]

So that chart,
These tires would handle 3000lbs over each axle at 50PSI? That's the general idea?
http://www.atturo.com/moto/trail_blade_mt
Load range and speed rating: 119Q 8PR LR D

no, 3000 for each tire so 6000lbs per axle.

I asked the guys at discout tires for a chart for my specific tires and was told that all tires go by the same chart according to the load rating marked on the side walls.

So,
For our trucks and their capacity, that would be more than enough.... Correct?

[verdesardog]

yep, way more than enough! Even for my Cummins truck.

[azracer]

The biggest difference is the ride and feel. The D rated tire will yield a better ride and more deformation on obstacles. However If you tow or haul heavy you will get a squishy and shifting feeling that the E rated tire does not have due to its higher pressure and stiffer/thicker sidewall. You can get by on D rated tires just fine but will have a more secure feeling with the E rated tire for heavy loads or towing. LT tire is also more associated with trucks and heavy loads than a "P" metric tire is, even though they can be the exact same maximum weight rating at their maximum PSI.

My Toyo ATII is a 121R load range, so it is rated for 106mph and 2150@35psi and 2500@45psi as shown in the E2 chart. The chalk test confirms I'm at or very close to the correct pressure when I am running the about 35 rear and 45 front pressures. I carry little to nothing in the bed and that is why 35psi works for me.

I did notice the E rated tire was much more responsive to steering input, has a better on center feel and feels flatter in turns with less sidewall rollover. I also noticed the E rated tire was a little harsher ride, likely due to the stiffer sidewall and slightly higher pressure. With the D rated tire I was @32 rear and 40 front but with a .5" narrower wheel and about 1" less wheel offset than I have now with the H2 wheels. The changes in wheel and tire made me have to relearn the handling characteristics of the truck all over again, (yes it was really that different). Truck feels totally different and the best way I can describe it is that it is a sportier feel as it were now with the E rated tire on a .5" wider wheel with an inch more offset in the H2 wheels.

Note: When checking your "load range" be sure you use the correct chart as the D1 and E1 charts are for the high pressure tires and the D2 and E2 charts are floatation series tires or lower pressure tires associated with the larger tire sizes. Just don't use a E1/85 psi chart for an E2/65psi tire is all I'm saying.

[verdesardog]

Yes you do need to use the correct chart. If you like your E rated tires use em. I'm not trying to change anyones mind, just educate people that have no idea about real life tire care. A lot of handling feel does have to do with wheel type, size, offset etc. also.

I like my D rated 121 load index at 35pis when driving with no load, they give a nice ride and hug the road nice. I do air up for heavier loads, that's why I have 200pis OBA on my turck.

[cruz]

The biggest difference is the ride and feel. The D rated tire will yield a better ride and more deformation on obstacles. However If you tow or haul heavy you will get a squishy and shifting feeling that the E rated tire does not have due to its higher pressure and stiffer/thicker sidewall. You can get by on D rated tires just fine but will have a more secure feeling with the E rated tire for heavy loads or towing. LT tire is also more associated with trucks and heavy loads than a "P" metric tire is, even though they can be the exact same maximum weight rating at their maximum PSI.

azracer is right on the money with the above statement. The right tire for what you do with your truck is the way to go, that's why the tire mfg.s give us so many choices. Although I don't need an increase in carrying capacity to haul my camper, the E/10 with a stiff 3 ply sidewall helps with hauling my camper on and off-road. The ride unladen suffers very little IMO.
I'm running Falken Wild Peak A/T LT 295/70R17 @ 40lb front and 38lb rear empty most of the time.

[Cactus Red]

Had D rated BFG's, and they were too soft to air down for snow/sand use. I found that at below 20 psi they got too soft, and I lost a bead in conditions the E rated tires don't.

They were also too soft to tow with - the camper changes the handling dynamics a great deal. So, my last two sets have been E rated, and they have performed as expected.

Sent via gigawatt laser...

[wingerak92]

So, according to this chart (I finally weighed my truck) with 4160lbs on the front axle and 2620lbs on the rear I would need less than 35lbs on my stock size duratracs (load range D 121).



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[azracer]

So, according to this chart (I finally weighed my truck) with 4160lbs on the front axle and 2620lbs on the rear I would need less than 35lbs on my stock size duratracs (load range D 121).



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I would do the chalk test because the rim width, track and axle location in relation to said weight all have an effect. So the chart is a quick down and dirty guide but real world fine tuning is a good idea. I found that unloaded with a full tank of fuel the D rated tires needed 40>42 F and 30>32 R my E rated tires on a wider H2 rim needs 44>47 F and 33>35 R. So there are quite a few variables not to mention personal ride preferences and intended use. So you can find as much as a 10psi swing in a given tire with the same loads but different rims etc.