Mileage shocker!

[2Gen3Gen]

MY 04. 5 got an awesome 23. 9 mpg(overhead) (hand calculated at 23. 3)at 68 mph by using the cruise control from Grants Pass Oregon to Sacramento Calif. last week while visiting my new grand daughter. That is by far the best this truck has ever gotten. On the way back home, I did a test. It was 23+ at 68mph but at 70 and above, it drastically dropped to 18. 5 ... I guess that the under 70 rule will apply on my truck until fuel prices come back to earth.

My wife snapped a picture of the overhead just for kicks! She was impressed.

I might also add that from Redding to Ashland on I-5, I got 17. 9 at 65mph in the wind and snow. I think my truck is finally breaking in! Im now just under 9k miles! Oo.

 

[klenger]

Don't you know that the 600's are supposed to get 3 MPG less than the 555's? At least those are the reports from the non 600 owners.

 

[DEM123]

That is great!! My 325/610 is getting 20. 2 at 65 mph with only 1000 miles on it, can't wait till it breaks in!

 

[JWChessell]

Grant's Pass, OR is in the mountains. Sacramento, CA, although 100 miles inland, is less than 100 feet above sea-level -- it has a deep sea port; ocean-going ships do not have to traverse any locks. One of the reasons your mileage was so high is that you were going downhill.

 

[2Gen3Gen]

Don't you know that the 600's are supposed to get 3 MPG less than the 555's? At least those are the reports from the non 600 owners.

I had a 555 before my 600. I thought my 555 got better until last week. Now my 600 is getting much better. I guess that the winter blend fuel is gone in my area.

 

[bombero]

Did you get the TSB reflash done? Mine gets 13 around town and 17,5 on the highway @65. My overhead readout is a joke. I came down a long grade (donner) never touching the go peddle. The readout stayed at a steady 12. 5. Needless to say I am not a happy camper!!!!

 

[lmills]

at 4,000 miles I got a best of 21. 8 hand calculated. Funny thing was it matched the overhead also. I never was much of a believer in the over head till then. I usually just use it as a gauge of how heavy I have been on the throttle. That was running to York PA and back home on route 15 with the cruise set just under 70

 

[jimnance]

Grant's Pass, OR is in the mountains. Sacramento, CA, although 100 miles inland, is less than 100 feet above sea-level -- it has a deep sea port; ocean-going ships do not have to traverse any locks. One of the reasons your mileage was so high is that you were going downhill.

Grants Pass is 1,000 ft MSL and Sacramento is +/- 50 ft. Not much difference there. I'm very impressed as there are some big rocks and lots of up and downhill driving for about 125 miles of that trip. I just drove the same trip in a Ford Tauras (rental car) doing 70 MPH average and only got 22 MPG.



My '03 555 would only get about 20 MPG on that run a 68 MPH. He's got a keeper, that's for sure.

 

[2Gen3Gen]

I had the flash done 2 days after the truck was new. I had about 500 miles on it.

 

[DocDetonancour]

I've seen 23 on my 96 and on the 04. Seems that everything has to be just right and these CTD will do low 20's. Doc

 

[2Gen3Gen]

I've seen 23 on my 96 and on the 04. Seems that everything has to be just right and these CTD will do low 20's. Doc

The weather was about 70 degrees and no wind. I really hope this is the beginning of a good thing! Oo.



All winter I feel it must have been the winter fuel. That is the only thing I can think of.

 

[ndennis]

2Gen3Gen: While refueling my 04. 5 3500 SRW, the station pumps consistently shut off 6-7 gallons shy of being full. The only way for consistently accurate fuel calculations is to consistently fill to the rim. Ambient temps and wind direction play a measureable role in the fuel mileage also.

N Dennis

 

[Grizzly]

My experience in my 95 differed widely with brands of diesel and speed. I got my best mileage with Chevron and Texaco. Don't know about my 05 yet. With 500 miles on the odom on the 05 we averaged 15. 5 mpg at not more than 65 mph with varing speed on a trip from Albuquerque to Las Vegas, NV. Mountains most of the way. No load on the truck, except my wife's mega tons of luggage. Both trucks are dually's and 4x4. Not sure how much less mileage dually's and 4x4's are suppose to get. Grizzly



Note licence plate, it says GRIZZLY

 

[2Gen3Gen]

2Gen3Gen: While refueling my 04. 5 3500 SRW, the station pumps consistently shut off 6-7 gallons shy of being full. The only way for consistently accurate fuel calculations is to consistently fill to the rim. Ambient temps and wind direction play a measureable role in the fuel mileage also.

N Dennis

I use a 5 gallon can to top my tank off before a trip, which I take back home after the fill up just not to tick off the guy behind me. Yup, I need to do the tank vent someday, but it really isn't on the top of my list. All other times, I use the same station and same pump at in the same direction. I feel that is rather close to the same level of a fill up as you can get. For the record, my wife has been driving my truck to and from Ashland for the past few days due to the weather cond. She ALWAYS gets 1 - 2 mpg better that I do because of her driving habits. I would expect that my next tank will hopefully hit the 25mpg. She always got over 20 mpg in my Yukon XL when I never went much higher than 17+. Just a very light foot.

This morning, I took the Hemi to my sons school and couldnt keep the tires from spinning. Mostly because we were just having fun. The tires would spin and my kid would turn to me and just reply, "Can you say HEMI?" I had to chuckle! :-laf HAd I taken my Corvette this morning, I would have been all over the raod as its raining cats and dogs. My Vette has NEVER seen a single rain drop in its life. . Unwritten law, You NEVER drive a Vette in any weather under 70 degrees and sunshine! Hey, Its a Vet!

 

[Alan Reagan]

At 7,000 miles I have gotten 20. 5 (calculated) on my last two fillups. That's up 1 to 1. 5 mpg average. My overhead is showing 19. 9. It's trying to catch up. I'm going to Charleston this weekend. That's a 500 mile round trip so I'll see how she does at sea level.

 

[JHardwick]

2Gen3Gen: While refueling my 04. 5 3500 SRW, the station pumps consistently shut off 6-7 gallons shy of being full. The only way for consistently accurate fuel calculations is to consistently fill to the rim.

If the pump shuts off, and you hit it once more, it's full. The fuel gage will verify that. Stuffing an extra 6 or 7 gallons in will make the overhead read high. Hand calculations will be accurate as long as the same fill procedure is always used.

 

[2Gen3Gen]

If the pump shuts off, and you hit it once more, it's full. The fuel gage will verify that. Stuffing an extra 6 or 7 gallons in will make the overhead read high. Hand calculations will be accurate as long as the same fill procedure is always used.

I do my truck the same with EVERY fill up!

 

[ndennis]

JHardwick: My hand calculations are within 0. 5mpg of the overhead readout(usually better than overhead). Fueling this 3rd Gen is a bigger PITA than the Ford I had(which was solved by Transfer Flow, Inc). It is truly amazing how much diesel foam is trapped in these 3rd Gen trucks. That extra fuel I stuff in there actually displaces all the foam that is generated during the fueling process. My 2000 does not trap that much foam. Maybe a gallon max to the rim, but this 04. 5 is a whole different story. I am sure this is caused by the venting system of this tank(probably designed for gasoline). I have not had the time to install the fuel tank vent mod that is mentioned on this site. I have a lot of ground to cover every day and I can not afford to leave 6-7gallons behind every time I fill up. After filling to the rim, I do not lose any fuel to overexpansion because the truck does not stay in the off position long. As long as you are consistent in the way it is filled, your calculations will be accurate. For me, when the pump shuts off, I can not honestly say if there is 3" of foam in the tank or 12" or maybe even 20" of foam. I get around that by filling to the rim.

N Dennis

 

[JBlock]

There a kit out to solve that filling problem and it makes it into a 38 gallon tank, just don't fill the tank all the way in real hot weather and then go park it. The heat will expansion the fuel will push it out of the tank.

 

[Russknh]

do a search on vent kits being sold here