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Tire Pressure from dealership

MPDamon

MPDamon

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Had a puncture so had the shop at work patch the tire. They put 45 back in the tire which was way off from my other 3 tires which were at 58. They could have been at 60 from when I purchase it. Door does say 55 front/45 rear. So what's correct? Did they have them to high from the factory?
 
Rebels get 55psi in the front and 45 psi in the rear.

Sent from my GM1917 using Tapatalk
 
Mine were all at 60 when I bought it, I looked at the door and lowered them to 55/45
 
I think they all came at 60/60 but yes they should be 55 front 45 rear. My dealer never adjusted mine either.
 
Mine came from the dealer with 65 psi in all four. 😧 Quickly put 55 front 45 rear. Much happier with the ride at stock.
 
That is insanely high pressure for a half ton. Very poor tire size choice on Ram's part for the Rebel.
 
Marshfly said:
That is insanely high pressure for a half ton. Very poor tire size choice on Ram's part for the Rebel.
Click to expand...
The Rebel comes with E-rated tires (80 psi max cold) compared to the other 1500 models.

My ORG truck came with C-rated tires and I swapped to an XL-rated tire. Still 50 psi max cold and I don't run them below 40 psi.

My last truck was a Ford F-250 with E-rated tires and I never ran them below 60 psi. I prefer to maintain closer to load capacity of the tires (and also don't like all the sidewall bulge at lower pressures either).

An E-rated tire is rated for ~3400 lbs @ 80 psi. At 55 psi that drops to ~2600 lbs and at 45 psi it's down to ~2300 lbs.
 
That E range tire at 45 psi with a weight rating of 2300 pounds provides a total of 9200 pounds of carrying capacity.
My 1500 Larime with C range tires LT275/65R18C only asks for 38PSI in all 4 tires per the door sticker
The tires are rated for a max of 50 psi and 2535 pounds load each.
 
LouNY said:
That E range tire at 45 psi with a weight rating of 2300 pounds provides a total of 9200 pounds of carrying capacity.
My 1500 Larime with C range tires LT275/65R18C only asks for 38PSI in all 4 tires per the door sticker
The tires are rated for a max of 50 psi and 2535 pounds load each.
Click to expand...
No argument from me that the tire capacity at the "recommended" tire pressure on the door sticker will meet the requirements to support the ratings published by FCA (GVWR, GCWR, GAWR, payload, and towing).

While most are happy with the recommended pressure I prefer a larger margin (more capacity) along with a firmer ride (probably a hold-over from the 11 years with my F-250).

Most will call me ridiculous with my capacity "overkill" but I've always run my E-rated tires within 20 psi (cold) of max and my truck tires (C/XL-rated) within 10 psi (cold) of max. My bed is usually empty, or close to it, so I usually run my rear tires 2 psi lower than my fronts.

I'll make small adjustments based on tire wear. I've run my Ridge Grapplers from 42-46 psi since I got them and currently have 42K miles on them with good treadwear. I should get to at least 50K before I get to the wear bars and my tire shop pushes me to get another set of shoes. Not bad for a 'hybrid terrain tire' (mud/AT) with no mileage warranty.
 
brian42 said:
The Rebel comes with E-rated tires (80 psi max cold) compared to the other 1500 models.

My ORG truck came with C-rated tires and I swapped to an XL-rated tire. Still 50 psi max cold and I don't run them below 40 psi.

My last truck was a Ford F-250 with E-rated tires and I never ran them below 60 psi. I prefer to maintain closer to load capacity of the tires (and also don't like all the sidewall bulge at lower pressures either).

An E-rated tire is rated for ~3400 lbs @ 80 psi. At 55 psi that drops to ~2600 lbs and at 45 psi it's down to ~2300 lbs.
Click to expand...

Do the Rebels have more than 3900# FAWR and 4100# RAWR?

I have E rated tires on my 1500. For the GAWR of the truck I run them at 34 and 30psi according to the tire manufacturer's load chart compared with the stock tire pressure and rating. They are rated at 4080# at 80psi.

Ram chose a ridiculously high pressure for the weight of the truck resulting in a harsher ride than necessary. That's not an opinion. It's the facts according to the TRA load charts that are standard across the industry.

An LT 275/70R18 Load range E is rated at 3640#. Not 3400#. According to a load chart, 40psi in the front and 35psi in the rear is sufficient for the 1500 GAWRs. 40psi gives you 2270# per tire and 35psi gives you 2070# per tire.

Your load rating assumptions are incorrect but giving you the benefit of the doubt, there is zero reason to have 5200# of tire capacity with a FAWR of 3900#. A diesel 3500 SRW weighs 5000# in the front. 2300# in the rear is better but still 500# higher than the RAWR. Stock 3500s do not have tire pressures with that much overhead.

Here are the charts. Even though this is on Toyo's website, these are the same exact charts used by every manufacturer for every tire size.


Also, considering your post above about running significantly higher than recommended pressures giving you more "capacity." It also decreases traction and handling due to less conformance with the road. If you need more capacity, buy an HD truck.
 
Rebels do not have any special drivetrain.

There is a Max Tow package for the 1500 that has a Dana Super 60 rear axle instead of the Chrysler 9.25". I'm not sure if the Dana is semi-floating (GAWR 5500 lbs) or full-floating (GAWR 6500 lbs). I have never seen a DT that's had the beefier axle in back and I'm sure it's an incredibly small percentage since the standard rear axle is more than enough to deal with whatever you get that's within the trucks published limits.

I'm not sure the reason why RAM put E-rated tires on the Rebel. The only 2 things that come to mind are that they have a tougher sidewall for off-roading and there is a much larger selection of E-rated off-road tires than C- rated or XL-rated.

I used the same Toyo tire chart but made some general assumptions (rounded some numbers) as tires vary slightly.

As you said E-rated tires are excessive on the 1500 which is why you can run them so low and still maintain the needed load rating to support the truck. Regardless of margin and safety, I personally don't feel comfortable running tires at nearly 1/2 of the rated pressure.
 
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Bought my 2019 Rebel a few days ago. Dealer had all 4 tires @ 60 psi and I immediately deflated them down to 55/45 per the door sticker. Dealer also said the 5.7 Hemi can take 86 octane without issue...so you know...
 
ST4T1ST1C said:
Bought my 2019 Rebel a few days ago. Dealer had all 4 tires @ 60 psi and I immediately deflated them down to 55/45 per the door sticker. Dealer also said the 5.7 Hemi can take 86 octane without issue...so you know...
Click to expand...
You are going to trust a dealer that doesn't even inflate your tires correctly. :unsure:

Perhaps the dealer should read the Ram Manual for the 5.7 HEMI Engine. :rolleyes:

89_Octane.jpeg
 
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