LT Tires and Towing

[Meeker]

I haven't seen this mentioned on any threads in the last few years, so I thought I'd share my experiences towing with 2 different type of tires.

2018 XLT came with the Michelin Primacy tires. Towing my 2016 Cougar 21RBS I have to be very careful to keep the tongue weight and cargo in check to meet the RAWR limit. But with my WD hitch adjusted properly and everything I could think of to compensate I still had some sway in cross-winds and when semis pass.

Swapped the tires for Michelin LT AT/2 (the actual LT version, not the P version of the same name).

The dealer did the swap and inflated them to 44 psi saying that's the appropriate number. Well, my first tow I had even more sway than before! I finally used my portable compressor to pump them up to 55 psi (warm) and it was a night and day difference. Nearly rock solid - as good as we can get with Independent rear suspension.

I'm now running at 55 psi cold, and I cannot say there's a difference in ride quality (but my covid butt may be absorbing the extra jolts).

I think the 44 psi came from the Michelin load rating table - it matches the dry weight of the Expy. But, at the RAWR it should have been over 50 psi. So, if you're in this same position, look at your tire pressures!

Just to round out the story, I noticed a drop of about 1 L/100km fuel efficiency with the LTs at 44 psi, and not sure if that improved at 55 psi (I'm assuming it will). The winter traction is definitely much better (although not up to winter tire levels on ice). As always, YMMV.

 

[JasonH]

What made you go with LT tires? My understanding is that the ST tires are made to withstand increased lateral loads and sidewalk flex, and the correct trailer tire upgrade is a D or E rated ST tire.

 

[Dice Roll]

What made you go with LT tires? My understanding is that the ST tires are made to withstand increased lateral loads and sidewalk flex, and the correct trailer tire upgrade is a D or E rated ST tire.

an ST tire goes on trailers only. You can run LT tires on a trailer, just take 11% off the load rating due to side all flex and the heat it creates. An st tire is super stiff and would bounce your brains out

 

[JasonH]

an ST tire goes on trailers only. You can run LT tires on a trailer, just take 11% off the load rating due to side all flex and the heat it creates. An st tire is super stiff and would bounce your brains out

My bad, I thought you meant you swapped your trailer tires to LT.

 

[Meeker]

My bad, I thought you meant you swapped your trailer tires to LT.

Yup, to clarify I swapped the truck tires only.

I almost made a big error and got the P-rated ones though - I had my credit card out and then I noticed the max load wasn't what I was expecting on the sidewall. Too bad because they were half the price...

 

[Expedition Dave]

What is the max tire PSI on the sidewall for that tire?

 

[Meeker]

What is the max tire PSI on the sidewall for that tire?

80 psi

All specs: Michelin LTX AT/2 LT275/65R18/E123/120R LRE (max load 3415 lbs @ 80 psi, orig. tread depth 17/32")

This table shows the max axle load allowed for a given tire pressure (so for single = 2 tires on rear axle, my 4380 lb GAWR-R means I need a minimum of about 42 psi with these tires).
But I find I need much more than that to get low sway.

 

[Artie]

Why not do a chalk test on the tires? You may be over or under inflated still.

 

[RustyOval]

Frankly on my 09 I did not notice a big difference towing my 7,000#+ camper when I went from extra load tires to LT tires. The original 111-112 load rated tires were terrible, but the extra load 114 tires were a great improvement. I always maxed out pressure at 50# with my extra load tires. My LT tires could take up to 80#, but I would run them at about 65#.

Now with my 2018, I just put on extra load tires because I had good experience with them and I think for my purposes LT tires are overkill. JMO. Be careful with your pressures because some "Auto Places" have no idea what is correct and use the info on the door sticker... that information is good only if you are putting OEM type tires back on the vehicle.

 

[Meeker]

Thanks RustyOval and Artie - I'd love to try the chalk test, just waiting for the rain to stop (which hardly ever gets said in Calgary but it's 2020 so...)

You know, I never tried putting the max pressure of 44 psi into the Primacys. I should have tried that - probably would have helped with the sway. In the end I also wanted better winter traction which these LTs give me, so I was upgrading anyway.

 

[Dr0idattack]

When towing I run my LT in the 70s; running at 44 would seem too low. Also what WDH did you go with?

 

[Bigfishfin]

My recent trailer/tire experience...I just purchased a new to me, 2017 Outdoor RV Creekside 21RBS trailer including an Equalizer 4 way hitch, (these trailers are known to be heavy). I had been focused on replacing my original Goodyear tires before next winter, but because of a little uncomfortable "drifting" in strong winds and when passing large trucks, I installed Falken Wildpeak AT3W LT, load range E tires. I originally pumped the tires up to the maximum 80PSI and the ride was really uncomfortable for my dentures, but the trailer just about rock steady. I have now dropped the pressure to 60PSI with the ride now comfortable and the trailer just as steady...I am happy!...

 

[Meeker]

When towing I run my LT in the 70s; running at 44 would seem too low. Also what WDH did you go with?

My WDH is the Blue Ox, 1000 lb bars. The trailer salesman set me up with 750 lb bars originally based on the dry tongue weight - I upgraded because my measurements were always closer to 900 lbs.

 

[JimmyM]

I switched from P to LTs on my 11. When NOT towing the tires are set to 35. Ride was fine. First time towing my 6500lb TT with the LTs, I inflated the rears to 50psi (80psi max). HUGE improvement over the P tires with respect to how well the truck handles cross winds and passing semis. When I used to tow with the Ps, I'd inflate them to 45psi (51psi max). I also added Sumo Springs coil "spacers" in the rear. The truck doesn't squat as much now. I use an Equalizer brand WDH. I never had issues with actual sway, but a semi would push the back of my truck around. No longer.

 

[iamretired]

2015, I got wranger LT tires rated 80PSI, when using trailer I use 60psi, 50psi without trailer, both tire pressures feel ok, stupid tire shop always wants to lower to door tire suggestions.

 

[wakeboarder]

On my 2006 Silverado, LT tires made towing less bouncy than P rated tires. I think it had 18 inch rims. On my other vehicles w/ 20’s P - rated, I did not have bouncing. I think rim size has a big effect as well.

 

[LyoddChrissmiss]

JimmyM, how well do those sumo springs help. I do have a bit of sag when my TT is hooked up even with my blue ox wdh.
I’m thinking on the purchase

 

[JasonH]

I switched from P to LTs on my 11. When NOT towing the tires are set to 35. Ride was fine. First time towing my 6500lb TT with the LTs, I inflated the rears to 50psi (80psi max). HUGE improvement over the P tires with respect to how well the truck handles cross winds and passing semis. When I used to tow with the Ps, I'd inflate them to 45psi (51psi max). I also added Sumo Springs coil "spacers" in the rear. The truck doesn't squat as much now. I use an Equalizer brand WDH. I never had issues with actual sway, but a semi would push the back of my truck around. No longer.

I considered this upgrade, but we only tow 10 to 20 percent of our total miles. Did you notice any impact to mpg daily driving? We're usually around 15.

 

[Lou Hamilton]

I had LT tires on my Pilot for towing. Loved them. Waiting to put LT tires on the Expy. Towing is good enough with the stock Hankooks, but I think could be a bit firmer with the LTs.


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[Dice Roll]

Do LT tires hurt the ride on these? I have the 22s. Will only occasionally tow, so more interested in the ride. I’ll be sticking with a highway tread and not AT types.