Yet another BFG Tire fail.

[BajaSportsmobile]

Originally Posted by BIGVANS

Looking back on 30 years of 4x4 experience this particular case sounds like a rock punch. Besides ANZAC's requested info. Did you air down for the off road, etc.

I would concur with the puncture assessment. The cut you described is just what a tread puncture with a larger object like a rock or metal object that was big enough to remain on the road and not stay embedded would look like. These punctures are more likely to happen when the tire is fully inflated than when it is aired down.

Typically tire failure due to "under-rating" is really related to heat buildup and structural failure over time because of excessive heat due to too much sidewall flex. While it is important to pay attention to proper tire application - 40 years of off-roading and 25 years of off-road racing have taught me that there are no absolutes. Ratings are simply guidelines, there is plenty of margin left and the rating is not the point that failure will occurre.

[Carl]

Just installed a set of 325/65/18 BFG AT's. Took off Nitto Terra Grappler 295/70/18.
Both E rated.
One thing for sure is that the BFG tire is thicker in most areas, certainly heavier due to size.
The ride is actually better which surprised me. Seems the extra width and style may have smoothed things out. I've owned six sets on various vehicles and love them.

Seems to me the big issue is running a lower rating than ideal, especially for a heavy vehicle.

[Jeffrey]

Originally Posted by BajaSportsmobile

I would concur with the puncture assessment. The cut you described is just what a tread puncture with a larger object like a rock or metal object that was big enough to remain on the road and not stay embedded would look like. These punctures are more likely to happen when the tire is fully inflated than when it is aired down.

Typically tire failure due to "under-rating" is really related to heat buildup and structural failure over time because of excessive heat due to too much sidewall flex. While it is important to pay attention to proper tire application - 40 years of off-roading and 25 years of off-road racing have taught me that there are no absolutes. Ratings are simply guidelines, there is plenty of margin left and the rating is not the point that failure will occurre.

I agree.

[ANZAC]

Originally Posted by BajaSportsmobile

Typically tire failure due to "under-rating" is really related to heat buildup and structural failure over time because of excessive heat due to too much sidewall flex. While it is important to pay attention to proper tire application - 40 years of off-roading and 25 years of off-road racing have taught me that there are no absolutes. Ratings are simply guidelines, there is plenty of margin left and the rating is not the point that failure will occurre.

Yeah, my point here is that he can buy extra margin by going one rating up. Technically my SMB could run D rated tires (though very close to limit) but the E sidewalls are just tougher and that buys you some puncture resistance, at least on the sidewall.

[JoeH]

Originally Posted by ANZAC

Yeah, my point here is that he can buy extra margin by going one rating up. Technically my SMB could run D rated tires (though very close to limit) but the E sidewalls are just tougher and that buys you some puncture resistance, at least on the sidewall.

And on the tread, no? 10 ply vs 8 ply I think. E-rated should be 3 ply on the sidewalls.

[Skywagon]

I believe that the BFG's have three ply sidewalls as well.....
Bill

[Stumpalump]

Add me to the list with a failure. 255/85R16E BFG KM2. Tread started to separate so it got very unbalanced. They have a 6 year warranty based off of your receipt or if you don't have it they go off of the date code. Good BFG standard warranty for sure and I was able to talk them into replacing both rear tires. Prorating, mounting/balance, road hazard ect for the 2 was just over 200 bucks but I got about 7000 hard miles on them so I'm happy. Thanks to Discount tires for their great service!
The tall skinny size yields good gas mileage but I think a van may need a little more beef.

[MadScience]

Had a 275/70R18 BFGoodrich Rugged Terrain T/A fail with complete tread separation and a large, sudden loss of pressure through a 10"x12" tear. Not entirely sure about the order, all within a second or less of each other. Pressure was 78 PSI a couple miles prior, since we checked them all after feeling some strange handling -- should have checked for bulges all around at that point, not saying there was or wasn't one, but checking would have been prudent with the data in this thread.

Luckily the tire that went was on the rear and I was able to keep the van straight(ish) when it went. I was driving at 70mph[1] at the time and didn't have anyone next to me. I don't think anything but the tire, the wheel well and likely the rim was damaged. Could have gone much worse.

The rears are IRC 4 years old and are honestly one of the things I try not to take any chances with. I kept all the parts and will see if my shop can help me evaluate what really happened and how to avoid ever running into this again.

[1] I5, perhaps slightly random that I was going the exact speed limit at the time, but I was since I was trying to track transmission cooling efficiency and my suspicion that my converter isn't locking up.

[REF]

78 psi is quite high, esp when cold, remember as tires warm the pressures increase which would put it at or beyond max pressure assuming they are rated at 80. Tire pressures have been discussed in other threads, and most of us reported running well below the max pressures, I'd look at running them a bit lower, try 65, but you could even go lower for more comfort without any issue. I run my 315 duratrac E's at F/R-55/60

[MadScience]

Max pressure is cold:

http://www.tirerack.com/tires/tiretech/ ... techid=196

Mine were far from cold. It was 90+ out and we had been moving for a bit before I checked them.