Maybe not. The E rated 285/70-17 GoodYear Adventure's on mine seemed to be working out well, but wanted a more scientific way of looking at it. First is a rock test, then a tire foot-print test and measuring how much closer the rim is to the ground per Harry Lewellyn's 25% test at bc4x4ArticleAirDown .

If anyone does similar tire testing, please post it here -- This might become a resource to compare different tires, especially those that are similar/same in size.

The rock pics are at 15 PSI, and the temperature is about 60 F throughout these tests. Remember, this is a just 32.8" tire on a 17" rim, there isn't a huge sidewall like the big tires have to wrap around rocks.

The first pic pinched the sidewall a bit. Where's my spotter
15 PSI doesn't look that low until this happens. Note how much the sidewall flexed without damage or slipping off.


This is closer to what I intended, partially on a rock. Looks like pretty good sidewall flexing to me.


And this shows tread deflection as the tire starts to roll up the same rock as above. Both pics were at the same time.


And an old pic from a trip last spring.


Next post will have the foot-prints

 

Next are some tread foot-prints. First is 10 PSI, about 85 square inches, which is little over double the area at normal road pressure. Initial bottom of rim to ground is 6 1/4" per Harry's Lewellyn's test methodology, and the drop while at 10 PSI is about 1 9/16" (25%). This pressure is for soft surfaces like snow and sand only.



15 PSI is about 72 square inches of road area. The drop was about 13/16". For rocks, Harry's guideline of adding 5 to 8 PSI to the 25% height pressure is in line with my experience.




32 PSI is about 40 square inches. The Jeep is empty, and the fuel rank is almost empty too. When fully loaded for a trip I'll run one or two PSI higher.

 

I run E rated Duratrac's at 30psi, on 2 door with SRC bumpers front and rear, winch. Seems fine to me but, I do not rock crawl and air down to about 20psi at Gulches off road park.

 

I ran E rated Pro comp ATs and they were garbage way to stiff at time I had even aired completely down and took the core out of the valve stem. (I ran beadlocks do not do this with regular wheels) even with them completely aired down they still had enough rigidness to hold the weight of my two door without looking completely flat!

 

Great write and read Mr.T this needs to be highlighted and placed in the "write up" topic area..

For the longest time I wanted E's for the simple fact that they are more of a road tire than an off road tire.. but with us not driving off road that much and seeing your post.. We'll be looking more towards the D tire.. I'm just tired of the C's.. and wanted something different for a change.

I look forward to seeing others with these same comparisons..

 

I run E rated Toyos on my 4 door and they do great. I run mostly sharp rocky areas and areas with lots of sharp sticks down timber etc and need the sidewall strength. I run 28psi on road and about 15-16psi. smooth on road ride and I never worry about a sidewall puncture off road. If all I played in was mud maybe a 2ply sidewall would be ok.

 

This is all in perspective of the driver. They only way you will know if they are too stiff for you is to ride in a rig with e range tires. Everyone has a different preference. Suspension will change how e rated are perceived as well. One guy will say yes, too stiff, don't do it, he regrets it, etc. the next will tell you they are great, no worries, no regrets, etc., etc.

Find a rig with a similar easer up as yours with the different range tires. No easy feat, but in all honesty, the only way you will know if they are right for you.

I have e rated, the stiffness doesn't bother me until I am on a pot hole heaven road, then I don't like them. Otherwise, no complaints, but I life a firm riding vehicle too.

 

For us lesser beings, how do E-rated tires compare to what you get on a stock Rubicon? Also, how much more weight do they add compared to same diameter but lesser rated tires?

 

I had stock Rubi tires for a few months before I upgraded. The new tires are E rated and slightly larger. I do not feel that there was a noticeable amount of difference in on-road ride. My suspension is stock.

 

One thing I'm NOT saying is that all E rated tires are going to ride the same as another tire of the same or different size. The poster above that let out all the air (with bead locks) and it still wasn't flat is a good example of that. According to Tirerack.com stock Rubi BFG KM's in size 255/75-17 weigh 48 lbs. GY Adventures in 285/70-17 are about 0.7" larger in diameter, 1" wider, and weigh 54 lbs. To me, both tires drive very similar.