Tire Pressure

[SamPap]

Well after almost 4500 miles and three different individuals telling me that my front tires look like they are low, I decided to check my tire pressure. It was about 40 psi all around. I filled every tire to about 65psi and what a difference. My overhead would usually display 13. 6 and now it consistently hovers around 15.



I know most of you guys are good about checking and maintaining proper tire pressure but let this serve as a reminder for the few of us that need it.



Cheers, Sam

 

[stevenknapp]

Any difference in ride?

 

[HOCummins04]

My owners manual has specific guidelines for towing, empty, front, rear, etc. . I think I am running 55 up front, 40 rear. Getting around 15. 75 MPG hand calculated with almost 2000 miles on the clock.

 

[EEdmondson]

My truck came with 42psi all around. I added 20psi to the front and left the rear alone. I will add to the rear when towing or loaded.

 

[klenger]

I think the dealers set them up low to impress potential buyers with the nice ride. I guess they don't care if you crash and burn when you load it up.

 

[opjohnny]

My dealer put 70 psi all the way around! Just to be sure I checked it with two diff gauges. She was hopping and skipping all over the place.

 

[swexlin]

These Generals on the duallies seem to be a little low profile, as I run about 50 lbs front, and they still look a little low - I think the weight of the engine. My BFGs looked like that on my PSD.



Even so, when I took delivery, the tires were NOTICABLY low - had 40 lbs. I asked the dealer to fill them to 50. Dealer should have done that before I even picked up the truck.

 

[DWordinger]

My dealer had the tires up to the pressure recommended by Dodge. I checked with a tire pressure gauge to confirm the dealer prep. I then dove the truck and checked the pressure with an ifrared thermometer. Compare the temperature of the outside tread to the temperature doun the center of the tread. If the center is hotter, the pressure is too high. If the center is cooler than the edges (it was) the pressure is too low. I added 10 PSI to both front and back above Dodge's recommendations and had more even temperature readings. I didn't notice any difference in the ride quality. The fuel milage has improved, but most of that is due to the engine getting broken in. I expect to get more milage out of the tires also.

 

[John - K5AWO]

The sidewall says to inflate to 80 psi. Now that sounds to me like it would be a little harsh on the bottom fleshy parts, but the milage ought to be better. I just checked my tires, and just like yours; 40 psi.



Hope the extra air will make my 16. 0 mpg somethin' like 26 mpg ... .



yeah, right... 3500 DRW & AT, I would be happy with 18+

 

[rfoust]

I always air up to max--always. The weight of the engine and the 700 lbs of shoeing equipment in the back really never makes the truck ride rough. Then again, the rougher it rides the more I feel like I am driving a truck and it doesn't bother me.

 

[John - K5AWO]

Originally posted by DWordinger

checked the pressure with an ifrared thermometer.

What a heck of an idea, and I got one of those infra red pistols. Never thought to check different areas of the tires.



Many tnx for the tip.

 

[stevenknapp]

What a heck of an idea, and I got one of those infra red pistols. Never thought to check different areas of the tires.



Hobbystores are selling keychain sized ones for tuning little nitro motors with for ~$25.

 

[SamPap]

The ride feels just a little harsher. It's hard to say because the next day I installed the Skyjacker D25 lifting springs and I think these springs are a bit stiffer. It could be a combination of the two.

 

[jimnance]

Originally posted by klenger

I think the dealers set them up low to impress potential buyers with the nice ride. I guess they don't care if you crash and burn when you load it up.

They sure do. I tow a lot, and generally leave the tires up in the 70-80 PSI range. The rdie may be just a bit harsher, but mileage comes up at least 1 MPG by carrying extra pressure in the tires.



I'f you are empty all the time I suggest 70 PSI in front and sixty in the back.



Just my . 02

 

[HOCummins04]

DWordinger and anyone else with an infrafred thermometer -



What tires are you running? I have the BFG AT's from DC - ordered that way.



Would the tread pattern make a difference in the temps?



To help clarify, when you post pressure increases, please state either starting or final pressure readings. If you went up 10 pounds and don't specify a starting point or end, we don't know where you wound up.



Thanks for the info. Very interested in tire pressure as it directly affects MPG.

 

[EEdmondson]

John-K5,

The 80psi on the sidewall is the max pressure for the max load capacity of the tire which should exceed your truck's capacity. I usually run 10-20% above the vehicle maker's recommendation but with a pickup the load has to be considered.

 

[DWordinger]

From the _Tire Inflation Pressures_ document that was packed with the Owner's Manual, a Ram 2500 4WD with a light load should be 50 PSI front and 40 PSI rear. With the 265/70R17 Michelin tires that came standard on the truck, I use 60 and 50 PSI front and rear for a light and no load. These are all cold pressures.



The tire's temperature isn't the important measurment. It's the difference between the center and the outer edges of the tread. High speed driving on the interstate will give higher temperatures than driving around town or through the wheat field. You will have different temperatures after driving down a straight road than you will driving down a curvacious mountain road. (I ment curvy twisted mountain road. What could I have been thinking?) As soon as you stop, the tires start cooling. As you spend the minute or two it takes to measure all four tires three times (outboard center inboard) you'll notice the last tire measured is cooler than the first one. I measured mine about a dozen times and took averages.

 

[klenger]

Here is a link to the document mentioned in the previous post.



http://www.klenger.net/dodge/3rd-gen-reference/2004-tire-inflation-pressures.pdf