Does anyone drive their CTD

[White Ram1]

like a gasser?



Meaning, 75 MPH to 85 MPH, in the 2,500 RPM range or up almost every time your behind the wheel, long drives or short?



If so are you seeing any issues?



Life span

Dependability

Maint costs

Fuel milage

Etc... .

 

[dunderkofler]

I used to. About the only thing I noticed was that the fuel mileage drops off dramatically above 70 mph. No other concerns (outside possible LEO encounters).



Dale

 

[SRadke]

Fuel mileage is the only thing you'll notice changes dramatically. At those speeds you'll loose several mpg over 60 mph but it'll still be better than a gasser at the same speed.



-Scott

 

[JMingledorff]

What they said. In GA most interstate speed limits are 70, traffic flows 80, and with 4. 10's I average around 16. 5 mpg. If I run 65 I get 18-19mpg. No worries longevity wise or anything.

 

[Bertram65]

I have run mine at high RPMs 2400-2500 RPM on many occasions, I have not noticed much of a difference in MPG if I am running 2000 RPM or higher. I have tried running different RPMs for entire tanks of fuel, I run down to southern Jersey frequently. I have never got above 18MPG no matter what speed I run, just the price of 4X4, 4. 10s, and automatic I guess.

 

[Joseph Donnelly]

78-79 on the speedo on 75 zoned interstates gives around 19-20 mpg solo, a little less with a trailer. No issues. Cummins designed the engine properly.

 

[DPKetchum]

Tires are not rated for high speed extended.

 

[RTillery]

I have 43K on my 04, mostly highway miles out here in the west. (I am in sales) Just did Denver to Albuquerque and I usually run or slightly push the speed limit at 75 to 80. No issues, it has been a great truck so far. Got just over 20 mpg's coming down here today. If I keep it around 65, I have gotten 22 hand figured so mileage does drop off with speed. I change my oil every 5k, air filter and fuel filter at 10k. Did transmission and rearend at 10k and will do again at around 50-60k. Still on original Mich's. Think they will go 55-60K.

 

[Ol'TrailDog]

TO ME, (something like imho), all my CTDs seem to have a sweet spot around 2K. So that's were we cruise. Unless circumstances dictate HURRY.

 

[Bertram65]

Tires are not rated for high speed extended.

What tires are you talking about? My LT265/70R17E BF Goodrich rugged trails that came on the truck are speed rating R, which is 106 MPH, there is no risk running sustained speeds below that.

 

[Makensmoke]

I run mine down the freeway an hour at a time 2wice a day 23-2500 rpms. I used to cringe and hold back, since subscribing and reading the confidence of some people who really know about the guts inside our CTD's I let er buck. I do get the best mileage around 2k though, but with 4:10's 2k takes alot of patience.

 

[RACE427]

55-65 mph !

You will find that if you can cruise the Interstate at a steady speed somewhere betwwen 55-65 mph you will see fuel mileage of 18-20 mpg. You need to be every steady on the accelerator pedal as though you have a raw egg under it. LOL The faster you go, wind resistance really kills the fuel mileage as the engine has to work harder. I do realize that 55 mph is no fun and seems to take forever to get where you are going!! Sometimes it is just plain fun to see exactly how much fuel mileage you can get out of a 7,000 lb. truck!! People who have never owned a diesel before will not believe you and even seem shocked when you tell them the numbers. Diesels are the most efficient 4 stroke Otto Cycle engines on the planet!!

 

[RACE427]

Holman and Moody

There was a TV news report about 12 years ago where Homan and Moody of NASCAR fame installed a Perkins 4 cylinder diesel in a compact car, small Ford. They were getting 75 mpg with that car and I would have loved to own one as a commuter from Long Island to NYC. Back then I was driving 100 miles everyday round trip to work and home. Even then it hurts your wallet with the prices of fuel. 75 mpg would be a wonderful thing especially today!! LOL Too bad Detroit does'nt see things they way Holman and Moody did!!

 

[Buddy's Ram]

I normally drive around the 2k range myself. But when I went out to Yellowstone, the speed limit through Nebrasks was 75, so I set the cruise on 80 and let her rip, all day long. Other than fuel milage falling off no problems.

 

[ttreibel]

You can run it at 3K all day long if you want. Just let it cool down (3-5 min) before you shut it off.

 

[Punkineater]

Being as this is my first diesel I wasn't used to the RPM range when I first bought the truck. I used to drive it all the time similar to the way you described, but I have found that I get optimal mileage by keeping it around 2k or a tad lower. As far as durability or longevity I wouldn't worry. I would imagine the 4. 10 guys run those RPM's on a regular basis.

 

[DarkRAM]

I run mine down the freeway an hour at a time 2wice a day 23-2500 rpms. I used to cringe and hold back, since subscribing and reading the confidence of some people who really know about the guts inside our CTD's I let er buck. I do get the best mileage around 2k though, but with 4:10's 2k takes alot of patience.

I'll second that with the 4:10's requiring more patience, but w/ 100mi rounder 5 days a week, squeezing every MPG out of her is worth it to me, besides it helps offset for the weekends when I cant seem to keep my foot out of it .

 

[Ereynolds72]

I was told that the higher RPMs maintain higher pressures in the torque converter decreasing the chance of slippage and keeping the fluid cooler. This was basically the determining factor when I decided to go with 4:10s. It made sense to me... . I'm sure others may not agree. Currently my daily commute keeps my speeds about 65mph and my mileage is about 16. 5mpg. However, If I'm on the interstate the truck stays at 2500rpm (about 80-82mph with 4:10s and 285s). I still get 15mpg. Not as good as I thought I'd get going into it but heck, it's a huge scary truck. I've got 80k on mine now and so far haven't have any engine related problems. (knock on wood) I had another old guy tell me to "drive it look you stole it!!!"



I too was leary of the higher RPMS but the truck seems to love it.



'02 QC 4x4

 

[6 2 Carl]

I love my 315's and 3. 73's. 75 mph = 2000 rpm

 

[CEpp]

2500? @ 65 mph? man, i all of a sudden like my taller gears...



i will have to disagree with this statement:

"I was told that the higher RPMs maintain higher pressures in the torque converter decreasing the chance of slippage and keeping the fluid cooler. "



if your truck is a auto, the convertor is in lock up at that point, your not going to see any noticeable improvement in cooling of the trans fluid in 500 rpm's (2000-2500), but infact your heat should increase expecially if u have a stock trans with any mods. plus the motor will run warmer running down the freeway @ 80-85 then when running 65-70.



there are a lot of factors that put tempatures into play.