cLAYH

On my old '92 CTD I had reduced the tire pressure to get a better ride. On putting them back up to the specified pressure I noticed that the fuel milage came up about 1-2mpg.

Since then I've kept my tires at the specified pressure as per the door sticker. Downside is that I wear out the center tread on my tires as I usually run empty or light 85% of the time

GASKICKER

I'd like to see more info on this.....

annabelle

I rotate every 5000 miles, and have gotten as much as 80,000 miles out of BFG AT KO's. I have averaged over 70,000 miles out of 12 sets of BFG's. I gained about 2 MPG inflating them to 80 PSI......wants wrong with your driving and tire maintenance habits?

tesla440

I with Annabelle .Bob. I've been doing that with all of my trucks. I usually see 60,000+ miles on a set of tires rotating them every 5000-7500miles depending on the tire rating (D vs E rated). All have even tire wear with no high or low wear spots. If fact my E rated A/T 275/70R18 have a bit over 30,000 on them right now & just look like may start showing signs of wear. I'm guessing I'll still get another easy 50,000 out of them.

.boB

Proper tire inflation gives you a flat contact patch for the given conditions. Variables are mostly tire design, weight, altitude, and temperature.

If you have even tread wear across the entire width, then your tires are not over inflated. You have a flat contact patch. Overinflated tires wear in the middle.

There are two stickers in my door jamb. One shows maximum tire pressure. And the other shows empty tire pressure. I used a tire pyrometer, and discovered the lower pressures are just about perfect with my Michelin tires. I also found out that with the loads I carry, the max pressures on the door jamb are too much.

cLAYH

Its good to see that the manufacture is starting to differentiate tire pressure between a loaded truck and an empty one.

None of my CTDs to date(1992,2001,2003) have had different ratings for empty vs loaded but it does make sense.

Another reason I want to go back to a SRW wheel. With a SRW I would actually raise and lower the pressure depending on load. With the DRW I put it to the sticker on the door an leave it as getting to those inside duals is a real pain.

NDanecker

Cheapest and easiest would be air up the tires at or near max and slow down to under 1900 rpms. I found I get the best mpg at the engine speed.

Anything else you do --- larger tires, gear swap, programmer chip, 15 foot rocket nose-cone......all will cost you $$$ and many people, in my opinion, are blinded by the "I get +2mpg doing this/that" and never figure out how long it will take to break even and make money with that mod. And I'm one of them!!!

larrybartlett

That's not what my President BoBo told me

DodgeDiesel61

Is that from the dream mpg meter? I highly doubt you are getting that kind of mileage, hand-calculated.

Keyser Soze

it was hand calculated, the over head read 31mpg, it was weird.. it was before the twins and w/37" tires.. i went 400 miles on 1/2 a tank a few times, i've done 700 on a tank w/out the light coming on a few times.. Maybe my truck is an exception to the rules cause since i bought it, its been different then a lot of the 05's i've been around..

Rednax

(Article) BULK TRANSPORTER NEWS 9/2008

"Five tips to control your tire costs and improve vehicle performance, safety

With tires ranked as the second highest operating cost after fuel, a solid tire maintenance program can help reap solid dividends. Knowing the proper inflation level for your truck tires is crucial. TMC Recommended Practice (RP) 235 states the following determines the correct air pressure for a given load:

• Tire size and load rating
• Weight carried on each axle
• Number of tires on each axle
• Maximum speed the vehicle travels during its operation

http://bulktransporter.com/fleet/tru..._control_0908/



(.pdf) FIRESTONE MEDIUM & LIGHT TRUCK DATA BOOK

(see pages 52 for truck fuel economy discussion; and page 64 (+/-) for load /pressure tables.) (Go to the man'f'r of your tires, download and copy).

http://www.trucktires.com/firestone/...ckDataBook.pdf

.

-What can I do to make the best mileage gains?


Run along about ten under. Only accelerate to 5-mph below that number. (70 mph highway, run 60, accelerate -- easily -- to 55, and then drift up a little). Keep engine between 1700-1900 for all miles traveled. Use the cruise control for every mile you can. (And don't start crying on here like the other sheeple about "gettin' runned over" . . you have mirrors, use them).

HOD-ISB

Great post Rednax. I didn't follow all the links but I do have a dispute. I can't agree with the cruise control suggestion. This is always suggested as a way to increase mileage, hell in the class 8s companies will try to entice drivers to use the cruise by increasing available power when on cruise. My point is it depends on the drivers focus and habits if cruise will help or hurt. These trucks have a very aggressive cruise, some of you may have noticed that with the cruise set the truck will actually gain speed going up a hill (sometimes up to 2mph on mine). I suggest if you can maintain a constant and steady speed then leave the cruise off and when you ascend a hill (especially a smaller one) allow the truck to loose a little speed and gradually let it return in the decline.
On longer trips, personally, I use the cruise and reduce the POD so the cruise is not so aggressive and when the terrain varies often I turn the cruise off.

annabelle

My cruise control does not exhibit any of the attributes you state. My cruise is very steady an with respect to holding speed ( no increase up hills), and it is very slow to react to correct speeds. My cruise control is very steady.

Raspy

Well, at least nobody exagerates around here.

HOD-ISB

Annabelle, That is interesting. All the 600-610 series that I've had or had experience with do. Maybe the triple nickles are different ?