So, the dealer will switch out my stock Pirelli P275/55-R20’s for BF Goodrich T/A KO LT285/55-R20’s before I take delivery of the truck. I have a few tire questions. I apologize for the list of questions, but tires aren’t cheap, and I hate to take a major hit in the fanny to change back to stock tires if the BFG’s are crap for daily driving (90%) and towing (10%).

1) The BFG has a wider section by four-tenths of an inch (11.7” on 9” rim) than the stock Pirelli, although the BFG is rated on a half-inch wider rim. I assume the actual difference in width will be remain minimal if the different tires are put on the same identically sized stock rim?

2) The six tenths of an inch OD (larger on the BFG) should not effect the tight turns in combination with the slightly larger section width?

3) As for the revs per mile (12 less with the BFG’s), how does this correlate into the speedometer? Should I have the speedometer recalibrated?

4) The BFG’s are rated at 2,835# at 65 psi. I can’t find the PSI on the 2,402# rating of the Pirelli, although I assume it is probably 55psi. Can the BFG be run at a lower PSI for ride comfort of daily driving and I just boost the PSI when towing? How can I effectively determine the PSI to run?

5) The BFG is only a load D rated tire. The Pirelli is not rated, although I assume a P-metric tire is a load C at best. Am I really going to notice any difference in the D for towing? How about ride comfort?

6) Lastly, I see no major differences in the Pirelli over the BFG’s, so I assume gas mileage shouldn’t suffer at all, if any. Can anyone confirm their experiences? I would assume the width being almost the same, the only influence on MPG should come from the tread pattern (depth is 1/32 deeper on the BFG), the width (0.4” on BFG), and weight (assuming the BFG is a fair bit heavier due to D rating). Thoughts?

Thanks to all ahead of time. I appreciate the input.

Smoke

 

1. Your new tires will always be just under half an inch wider whatever wheel they are on as the tire is just under half an inch wider(275 compared to 285).

2. You should be okay assuming you have a 4x4. 33" is the max on a 4x4 without any lift.

3. You will only be off by about 1 mph. You can get the difference here. http://www.discounttire.com/dtcs/infoTireMath.dos

4. No way would you run them at 65. They will be fine running them at 40-45. I would not go lower than 40. The Pirelli max is 44psi.

5. The Pirelli is a extra load p-series tire (passenger car). The p series tires in my opinion should never be put on anything larger than a Ranger.
Towing will be far better with the BFG, although you might notice a little harder ride. Do not be tempted to lower the pressure lower than 40. That 2402 of the Pirelli is not the true rating when used on a truck. Multiply that number times .9 to get the true max. http://www.tirerack.com/tires/tirete....jsp?techid=70

6. You might see a little difference in the mileage (lower), but it should not be that much.

 

I agree.

 

Thanks for the replies. I just talked to a tire shop that sells BFG's, and they said that BFG is one of the only manufacturers of a tire that will work on the 20's (comparable in size to the Pirelli), which have a 3-ply sidewall on a D-rated tire. They think the sidewall (3-ply) will be so tough I will sacrifice quite a bit of ride with the BFG. As a daily driver, I am a little aprehensive about switching to the BFG's. Is anyone out there that is running BFG's in this case? I am afraid running these BFG's will pu me back to the ride of my F-250, which is something I don't dare do for the little towing I do compared to daily driving. Of course, it's cheaper to upgrade now and get a credit comp[ared to buying BOTH sets of tires if the Pirellis are crap.

 

i am running the 285/55R20 BFG on my truck at 40 psi. they are great. the ride is actually softer then my factory 275/65R18 goodyears. my sppedometer is actually more acurate now then it was with the stock tires. according to my gps it is dead on. i highly recomend them.

 

Thanks for the reply, Paralyzer. My dad put them on his F-250 (well, has put them on several trucks), but on his current truk, it is amazing how quiet and soft the ride is over the Continentals he had. I am just concerned for a daily driver over the Pirelli's becaus I drive ALOT unloaded. The last thing i want is a rough ride again. I think I may try them and hope I won't regret it. It will cost me the $400-$500 to upgrade from the Pirelli's, and it would really such having a harsh ride knowing I paid for it!

BTW, I assume the Goodyears you speak of were the LT tires upgraded from the factory ($325 adder), correct?

 

One thing with the Pirellis is they get flat spots on them very easily. Of the truck sits for more than a few hours. I have them on my truck and for the first 10 or 15 miles you will get a shimmy in the steering wheel and a vibration in the truck. I noticed it more when it was cold out,(under maybe 50 degrees). I have heard a lot of people unhappy with these tires because of that. Also I had 25K on them and the sidewalls on 2 of the tires was split half way around, luckily that was covered under warranty. Just something to think about......

 

Well, I really thought I'd run the BFG's until I was told the LT285/55R20 is being discontinued. I called BFG to confirm this and they said it is so. Then, I recieved a rash of crap because I am changing to a tire size that isn't what came from the factory. I explained the LT-metric tire desired for towing a trailer, and all I heard was the BS about it not being an OEM tire. I guess I'm screwed either way. If I gamble with the BFG's (with a size that is being discontinued) and I have a blowout or damage a tire, I won't be able to find a replacement. If I go with the only other LT available (Michelin LTX AT/2), it is a load range E and will probably knock my teeth out for commuting AND it is only available in a blackwall - YUCK! Then, I guess I could stick with the Pirelli and deal with flat spots, shimmying, balancing, poor off road traction in mud, and no go in snow. So, I guess I either shut-up and ride the originals and hope towing is okay, or find another p-metric identically sized. WTF? Ford and their bastard tire sizes can kiss my @$$. I almost faced the same issue with Crapinentals on my F-250.

 

I know you don't like the black sidewall of the Michelin your interested in. But I can tell you. A Michelin in a E Range does not give you a harsh ride like many others. Not sure how they do it. From what I've read, LTX AT2's have softer sidewalls.

So, if blackwalls are something you can deal with. I seriously doubt you'd be unhappy with the AT2.

 

Points well taken. Thak you. I am seriously considering them even if they cost a wee bit more. I have heard the softmess of Michelin's is unbelievable for the E rating in the tire, too. I like the tread pattern, the likelihood of more tirewear mileage, and the likelihood of not sacrificing fuel economy (as much). I just don't like the blackwalls, and on a King Ranch, I think they'll look worse. I'll live with it if the price is resonably right. maybe I can get some of those stick-on whitewalls of yesteryear?

 

Well, I did finally find out that the BFG's I considered are actually MORE than the Michelin's by $100. I don't really know if spending $600 (BFG's) or $500 for the Michelin's is worth it for the dozen times this year I'll tow my 6,000# trailer and the six times I'll tow my 3,000# flatbed. I'd say maybe not, but with the crappy reviews I'm reading in the Pirelli ATR's, I'm wondering if I should keep them at all, or thnk about a less expensive P-Metric XL alternative like the Wrangler or something. HELP! Am I looking at the hole instead of the donut?

 

I highly recommend that a/t2

Michelin's sidewalls are always soft but they have a hard thread area.. Which is why you can get so many miles out of them.

My boss has them on his truck and i've drove it and love how they ride. They are not loud or hard, but he's never had any problems towing his 24ft car trailer with his muscle cars in them.

I was going to get them but michelin doesn't make a 35"

 

Thanks for the recommendation (and thanks to the others that gave me their input). As much as I hate to spend the money, I have heard too many good things about the Michelin's, so I pulled the trigger on them this afternoon. I'll run test pilot for the forum on these and give the real scoop in a few weeks after I get the truck and drive it a bit. Although I am not excited about blackwalls, the tread pattern looks great, and it also looks very "comfortable" for the driving I do. Thanks to all... again.

Smoke

 

make sure you post up pics of the new truck!

 

Well, my truck is built and hopefully is in the process of finding it's way to the dealer. I stopped at the dealer tonight just as they were unloading the set of Michelin LTZ AT/2's for my new ride. The guys were saying "Now that is a tire!" I couldn't believe how big they looked! I know they probably look big un-mounted, but I swear they are very tall in comparison to the Pirelli's. They make the 20's on my Superduty look short. I know they are taller by an inch, but it looked like several inches. I had to check the size.

Anyway, in my opinion, these are the replacements for the "built-forever BFG TA's". The tread design is deep and very massive, but it looks extremely well designed to be very quiet and do nothing but grab. There goes my fuel economy. The grabber edges look great, and the rubber feels soft. I can't wait to see them mounted n the truck. I think they will be phenominal for an all-terrain. To think I don't like blackwalls. When I saw them, I think I found something harder than the tires!