Many have you have read my posts on Centramatic balancer thread in regarding my difficulty with the new Dynatrac 245/70r/19.5 16ply load H tires that arrived on the new 19.5 Visions back in June. Could never get them balanced right the first 5000 miles. Horrible vibrations. 3 commercial truck tire shops deemed them defective in writing even having the equal balancing media removed. Due to ATD( American tire distributors) incompetent defect warranty procedures in regards of having to send tires back first and waiting 4 to 6 weeks for them deem tires defective. I decided to buy 4 new American made tires and deal with ATD after. Firestone 245/70r/19.5 14 ply load G.So here is my questions.. What is the best way to break in tires. Load TC right away, which I did last time with Chinese Dynatracs or drive truck for awhile unloaded? Also after having new tires mounted and balanced today three gentlemen at Wylie tire shop after I asked them to inflate rear tires to 100 psi and 80 psi in front tires politely suggested that I do not need to run that much in the rears. Told them I carry a heavy TC which most of the weight is on the rear axle but they still were adamant about not needing to that much. one shop owner stated he has hauled many heavy fifths and heavy equipment gooseneck trailers and never max psi his stock tires. I ran 80 in fronts and 100 psi with dyna tracs 245 16 ply load H.

Have you ever weighed the rig loaded to see what the tyre pressure should be according to manufacturers load tables.

I have no idea of the best way to break them in. I really didn't see any difference in mine with how many miles they had on the previous SRW. I saw the biggest difference with air pressure in the front. Do check the load tables for what you are carrying but my guess is 95-100 is about right for most SRWs. The pressure is what is holding the load, so dropping the pressure down to 80 in rear wouldn't get you all of the benefits of the F,G,H tires.I think I mentioned this on other threads, but my F450 that comes with 19.5s recommends 80 for the front for the max load - FAWR. Also, it suggests 75 in the 4 rears for the max load - RAWR.

My break in consisted of 9 days 1600 miles of freeway, secondary roads, Dirt FS roads and gravel washboard. but to tell you the truth the Toyo M143s on Vision rims ran just fine from the get go at 85 front and 100 rear with no fancy balancing needed.

I'd say drive around unloaded for a few hun'ert mile

To determine proper pressure, you need to know the weight they are carrying. If you do not know the weight, then run max pressure. Over inflated tires just have a harsher ride and may wear the center a bit faster. Under inflated tires tend to quit working, sometimes in a horrific life ending blow out.Never heard of a need to break tires in. On our dump truck and I'm sure with most big rigs, the tires are mounted and run hard. Think of it this way, when you put the tires on a fifth wheel, there isn't any break in period.

Best way to break in new 19.5 tires | Good Sam Community

32 Replies

BeatCJ
Explorer
Oct 03, 2014
msiminoff wrote:
This is the kind of thing that people who have never owned 19.5" tires and/or never experienced tread squirm say… Tread squirm is not the sorta' thing you "get used to" ;)

I drive several different vehicles with 19.5 tires, worn out several sets of OEM tires, went to 245/70R19.5. One of them had 285s, we changed those out to 245s because the inner sidewalls on the rear duals touched all of the time. I didn't notice any treadsquirm on those trucks. I have another truck that we replaced the 11R22.5 Michelins Load Range G with Goodyears Load Range H, 29/32nd original tread depth. The squirm was and is still noticeable. And maybe that's the issue, on the 7 different Fords with 19.5 inch tires I am familiar with, I felt no tread squirm. I should have qualified my response.
billyray50
Explorer
Oct 03, 2014
Hey Mark,
Thanks for the info. I will be loading the camper on tomorrow morning and already know my Weights loaded for my Lance 990 Legend. Had tires inflated to 85 psi in front and 100 psi in rear tires for TC loaded. Will be going on long trip in a few days. Already noticed improvement in handling after 75 miles empty with new Firestones with 75 psi all around. Not much squirm at all compared to the defective Dyna Trac 245s load H tires. New tires has less aggressive tread too.
msiminoff
Explorer II
Oct 03, 2014
billyray50 wrote:
What is the best way to break in tires. Load TC right away… or drive truck for awhile unloaded?

The best way to break in your new 19.5's is to drive… drive…drive! (while allowing time for the tires to cool between heat cycles of course). The tall tread blocks on 19.5" tires will exhibit a lot of "tread squirm" until they have gone through many heat cycles and worn down a bit. Your tires will heat more and wear more quickly when loaded, so if you can tolerate the squirm, I'd suggest that you load the TC and hit the road.
FWIW my Michelins were absolutely terrible for the first 1000 miles or so... today they ride like the truck is on rails.

The tire pressure should be set to match the load you are carrying, but never less than 75psi or you run the risk of having a tire de-bead (note that I often run mine as low as 60psi unloaded, but I do not recommended that others do this). If you haven't already driven your truck over a scale to see what your rig weighs loaded, this is the time to do that. I am sure that Firestone has an inflation chart available, use it! I As a point of reference, here's the one for my Michelins:

BeatCJ wrote:
Tires don't need breaking in. I suspect the people that noticed wander the first 1000 miles just got used to it.
This is the kind of thing that people who have never owned 19.5" tires and/or never experienced tread squirm say… Tread squirm is not the sorta' thing you "get used to" ;)

Cheers,
-Mark
billyray50
Explorer
Oct 02, 2014
Lawrosa, No my axle is a AAM 11.5 rated at 10,800 lbs. Same as a dually except hubs are longer. Stock 265 tires and stock 17 wheels from factory is why sticker is rated 6010.
jimh406
Explorer III
Oct 02, 2014
lawrosa, heat is generated in tires and there is a potential problem when the are overloaded for a given pressure. Otherwise, the typical E rated tires found on a F250/350 would suggest 80 for the front instead of 65. 19.5s are no different.
lawrosa
Explorer
Oct 02, 2014
Page 76 here states 110 psi @ 4540 lbs. load range G..

http://www.firestonetrucktires.com/pdf/Fstn_DataBook_2013_HiRes_r3.pdf

Dont make sense. If your going to say air them down to 95 psi then you should have got load range F's.. You would air them down to say 80 psi. But try that with the G,s you have and IMO you will generate heat..

You really have too much tire for the truck compared to your rear axle limit which was probably based on the original tires..

So the rear axle is not the 10k as you stated its 6K.....
wcjeep
Explorer
Oct 02, 2014
My dealer said to ride the 19.5's heavy and hard.
jimh406
Explorer III
Oct 02, 2014
I think anyone suggesting 19.5 fronts should be at max pressure hasn't tried driving a truck with the fronts that high.
Buzzcut1
Nomad II
Oct 02, 2014
lawrosa wrote:
Axle rating on my truck is 10,800.

Hmmm!! So tires are below axle ratings... Wonder what the original tires size say on door tag.

Again just me but I would air them up max cold psi loaded...With a 3400lb TC and the weight of the truck the ride will be smooth and stable.

Max psi on a 19.5 is 120 psi and it will ride like a rock
billyray50
Explorer
Oct 02, 2014
My truck sticker with stock 265 17x 8.0 GAWR front is 5200 and rear GAWR is 6010. From what i have read here on this site the weak link are the wheels and tires.