I run 55/55 on my 295/70/18 Cooper ST Maxx tires, sticker says 60/65.. I plan on dropping down a little more, may 50/45 just to see how it is, but waiting on new shocks/steering stabilizer before I do. When I load up the bed with 1 ton pellets for the pellet stove, it goes back to 60ish in the rear....

 

Great information all the above ^^^^^. Clearly I need to drop my rear tire pressure. F-350 BTW. Anyone that can tell me what the factory default is for the rear TPMS warning? I have Forscan so can modify it if necessary. Thanks for the input. The knowledge on this board is outstanding as are the folks who
willingly share theirs.

 

We haveTPMS which was mandated (by Obama) for MY 2008 and up passenger vehicles under the disguise of fuel economy

 

Well, some of you have it.....

The underlying issue is still the same: most people don't take operating a vehicle seriously, so they drive around with under-inflated tires, which does affect fuel consumption. And as noted in extreme cases, unsafe conditions. Without that "personal responsibility", the government thinks they need to step in. If people were more serious about operating and driving vehicles, we may or may not still have TPMS. It would certainly be an option, but maybe not mandated.

Now we are getting more and more "safety features" mandated on new vehicles, all in the guise of "safety." Backup cameras were the latest requirement. Soon they'll have to add blind spot monitoring, lane keeping assist, emergency braking, adaptive cruise, etc. We are removing the driver from the operation equation with every passing day. Systems designed to "help" drivers, when the reality is they are crutches and result in even less-attentive driving. "Hey, I've got AutoPilot in this Tesla, I'll just rest my eyes for a few minutes on my commute...."

 

I am ok with some of the "helpers", like the 360 camera, on a big a$$ truck, it is very nice to have. Self driving like the Tesla people around me, I want to cut them off on purpose. I hate seeing the millennials with their teslas and not even attempting to pay attention. face buried in their phone or tablet.. Drives me bonkers...

Cadillac has it right with the superdrive, if you look away for too long, close your eyes and fall asleep, it alerts you and kicks off so you have to pay attention..

 

I'm definitely OK with the features and manufacturers innovating/refining them to offer to shoppers. But I don't think they should be mandatory, driving up costs. I wanted the 360 cameras on my truck, since it is so large, as well as BLIS for the same reason. I've noticed with the bottom wide view mirror properly setup, I'll see a vehicle in my "blind spot" before the system does. I still think it was worth the optional cost.

But those were things I wanted, which might not be things that others want. Lane keeping assist would be a "hell no" for me, even with a massive dually, for example. Same with Adaptive Cruise. If the traffic around me is that thick, no way am I using cruise control. And as bad as the traffic is around here, someone in CA might look at it as a "must have" feature.


Wow, we've gotten a long way off the Tire PSI topic!

 

I’m one of those millennials you see driving my model X on autopilot and working on my phone at the same time. It’s the only reason I bought the Tesla and then bought another for the wife, because it worked so well. It’s a lot better than those playing on their phones with no autopilot.

 

I disabled TPMS with Forscan, because I don't even have sensors in my wheels. Stupid system. My 2016 Ram DRW had it right. It used a TPIS (tire pressure information system). It displayed tire pressures, but there were NO warnings or lights or chimes for low tire pressures. It simply displayed the tire pressures, and that was it.

 

I used forscan to lower the pressures on all 4 tires to allow down to 50 PSI, they dont alarm until 49 or so. I believe the stock settings were for 60 front, 65 rear, buts its been three years and I lost my notes on the Hex Code for the settings. Chalk test shows that cold in winter they are set at 55 psi is about perfect for wear.. They go down as low as 50 but haven't had a warning yet. With temps around 0 C in day, I am seeing 56-57 on all four tires, longer trips, fronts go up to 60-62, rears maybe a bit more depending unloaded.

 

Im still running mostly at least 55 in the rears and higher in the front. I have yet to get a TPMS warning. My 2007 GMC had early TPMS and the rears were giving me a light above 70. I wanted to run 55. In 08 the dealerships would not lower the TPMS setting as though it was a liability issue. I was telling them I was going to sue them if I slid off the road due to over-inflated tires. Finally my local mechanic got the proper hardware to lower my threshold to 50 all the way around. I wont bother with lowering my threshold on the 250 at this time as I actually seem to prefer the Michelins a bit hard.
Next time around I dont know. Looking at Nittos, Yokahamas, maybe Coopers. Not going as aggressive as the Duratracs. Im waiting to hear guys reviews of the Yokahama X/ATs in the snow.

 

I won't rehash what Mike said, he nailed it and has provided sage advice suggest you heed...that said lets look at the door jam sticker and understand what it implies:

Mike please comment if you have any thoughts on this.

I see the recommended TP based upon the max payload capacity. Possible I could be wrong, but I have spent a career reading AND writing AND applying tech specs and Mil-Specs.

 

Right. Max payload at that air pressure. But the tires might show a higher max load at even higher pressure. And different single or dual. They would likely put tires on that exceeded max payload by a safe margin. Those tires probably will take 110 as you found them when you picked the truck up. Some one looked at the tires and just filled them to max tire rated load.
And really, with a dually...its worse to be over-inflated in rain or snow while unloaded. Because theres twice the contact patch. Less PSI on the road making it more likely to lose traction.
The worse thing traction wise in a big truck was having to bobtail in the snow. 8 tires with no load spinning like everything was ice.
But not everyone has the ability to conveniently raise and drop tire pressure. So if your running loaded half the time your just better off airing up to appropriate pressure and keeping it there. I never lowered PSI in my big trucks to run empty. They stayed aired up to max pressure at all times. There were times if I was pulling some big leasing companies trailer with my truck and my fuel I would air their tires up hard for better fuel economy. And use the hand brake to slow down.
But for my purposes now... and I think for a lot of guys driving 3/4 and 1 ton trucks... these are heavy duty family trucksters used more for commuting and grocery getting than max hauling. With a few boat hauls a year and some camping trips. Cobby mud tires that see dirt 10% of their life.
For those applications airing down often softens the ride.
The chalk test really shows how the tread will wear.
I look at my tires every time I get in or out. Its genetic. I can see a problem. Hear it. If one tire looks a slight more bulged I bang on it. My 250 is just about to get a 10,000 mile service Ive put air in and out 10 times already. Changed the oil twice and about to do the 3rd. If a guy is going to just drive and bring it in for service or if a light comes on... they might be better off just airing to the door sticker and leaving i there.
I don mess with my 450s because they are likely to be loaded at any time. So I just accept the ride might be a bit more nervous while empty. My 17 has 1 tire that keeps losing air. I bang on them once in a while. When that tire goes thud I air it up.
Its easy when youve done these things your entire life. On a thread like this I hate to tell someone what they should do. If this is a guys first truck reading all this is going to make them feel like if they make a mistake they are going to blow a tire. I think you need to really be negligent to blow a good serviceable tire.
Want to make it more complicated? Running heavy in the summer down on Rt 10 compared to up on 80...Might want to stop for a leek more often and feel the heat and let the tires cool down. Thats probably more important than 10 PSI of air for sure.
I can talk a blue streak... Ill shut up now.

 

Expanding on a couple of points:
I picked up my new F 450 last Thur where I bought it about 40 mi up I 10 from me. The drove like a skateboard on ice, I was all over the roads. Hit a bump and slide across the road. The ride was bone-jarring. I would have turned around and gone back but they closed for the day when I picked up. I blamed it on the Truck Camper/Snow Plow package. The next day I decided to let out some air in the tires to soften the ride. To my shock, I had 110 in the front tires and 120 in the rear dually. Well good, grief no wonder it rode that way. Tires now have door jam psi and it rides like a completely different truck. TIP: The truck max payload dictates the tires, the tires do not dictate the truck. So go with door jam, but make sure your tires equal or exceed the max weight rating fo the truck and payload.

TIP: I grew up way out in the country on a ranch, we had cars, ranch trucks, tractors and they all needed air in the tires and it was all at different psi. How did we put air in all those tires? A hand pump. Back in those days, psi was more of a guess than anything else and accuracy in a gage was not much more than close. But my dad knew how to determine the correct air pressure. Mike refers to it as the chalk test and yes that works. But in the event, you don't a chalk bag there are other ways: We had dirt roads on the ranch and a short drive would tell the tape of the tape as they say in the boxing world. So will driving over some water in a rained on the parking lot. Anything that sticks to the tire tread enough to get a reading. From there it is simple: If the outer edges of the tire tread are marked and the wt3er or chalk has not rolled onto the sidewall then you are at the proper psi for you vehicle. If the chalk does not coat anywhere but in the center, you are way overpressure. Mitigate by letting out some air till you get a full contact patch.

To this day I do a walk around my truck and inspect my tires and my contact patch almost daily and when I travel at every stop. I trust what I see more than a gage...of the 6 gages I had in the shop I did a psi test the other day. Of those 6 I tossed 4 of them due to inaccuracy by more than 10%.

War Story: I asked my dad for a Sun Timing Light for Christmas for my car back in those days. I remember it was $49.95. A LOT of money back in the 60's. Dad said come on son, I will show you how we did it back in in my day in the 20's.

Put the car in gear and with the ignition off push the car to turn over the engine and put the timing mark the timing plate where you want it. In this case it was 12 degrees before TDC

Pull the number 1 spark plug and reinsert into the plug wire.

Loosen the distributor clamp.

Then he told me to hold the spark plug and put my finger in the spark plug hole and he would turn the distributor until the points made contact and that would be exactly 12 degrees before TDC.

Well we did and dad turned the distributor and I got hit with about 80,000 volts knocking me to the ground. Dad tighten the distributor clamp as I got up and I asked him why he did that? He laughed and said son, you will NEVER forget how to set the timing on a car again...he was right I still remember the procedure!

NOTE this no longer works on today's cars.

 

Yea... I still pump up bicycle tires and squeeze them to feel for proper pressure...on the truck tires we always carried something under the seat... a hammer would do. Truck stops used to carry a "tire billy" which was a mini billy club often with some metal to add weight to the front. You could hear very slight differences by the sound. No accuracy but having them all sound the same was good enough. Doubled as non lethal protection as well.
Usually the one that went thud would turn out to have a bolt or screw straight into the tread. So you would spit on it and see if it bubbled. No bubble? Pull it out... Bubbles? Screw it in tight and keep going. I remember running with a 9/16 head bolt for three days. Just kept it tight .

I was laughing like hell as I read up to your finding spark...Biggest problem with that is youll need to find a new "tool" each time...

 

Running max tire pressure will wear the centers out quickly. Especially on the rear tires.

I have put my truck on a CAT scale to get weights.

Based on weights and inflation tables for my tires, 65psi in the front and 35psi when not towing. When towing, I go to 58psi.

I got 84000 miles on my last set of rear tires doing this.