Diesel Fuel

[dhalltoyo]

Just put a new Duramax on the road. Did the break in as instructed. Varied the speeds between 50 and 55 mph. Ran first 100 miles around town before hitting the road. Ran another 100 to the first pick up point. Idles there for about 20 minutes while waitimg to load. Ran another 200 miles to the first drop off. Idle there about 15 minutes while unloading. Ran another 100 to the final drop. Finish off another 100 to a rest stop before shutting down. No problems.

Running less than 55 mph I didn't need fuel until 600 miles. Pumped in 27.5 gal of #2 from a pump out front at a Pilot station. The station was in Youngstown. About 100 miles down the road just below Akron I began to pull a few fairly steep grades. The engine was really noisy! Sounded like heavy predetenation on a gas engine. Ran out 1/4 tank and fueled up again at a BP station along I-71. The new fuel seemed to quiet it down for a while, but even between Columbus and Springfield, which is pretty flat, I would still hear that noisy rattle when pulling the slightest grade. At 55 mph it sounded normal as with my original tank of fuel that was provided when I picked up my van.

All gauges remained fixed and normal. No indicators warning of water in the fuel or low power. Sounds normal at idle and acceleration up to anything under 55 mph.

What is your best guess? Low Cetane fuel from the Pilot station?

 

[M A WEBSTER]

Sounds like you got some bad fuel. I've got a 7.3 320k on it. Buy 99% of fuel at the J. Have had no problem's with their fuel. When I buy from pilot I dont get as good mpg and the performance is not as good. I would shy away from Pilot. Also add Lucas fuel additive, $6.00 at miers verses $10.00 at the truck stops.
How do you like that duramax engine. I thinking about going with a cube van 15' box on my next purchase. Ford doesn't offer what i want under 10k so i'm looking at chevy or gm.

 

[LDB]

>Running less than 55 mph I didn't need fuel until 600 miles.
>Pumped in 27.5 gal of #2

Almost 22mpg on a new engine is great numbers. I've found the Power Service Diesel Fuel Supplement with Cetane Boost in the white jugs gives a noticeable improvement in the engine running smoothly and helps mpg by about 3-5% in my truck. Keep us posted on how your truck does. A lot of folks are curious about the new Duramax.

Leo Bricker, owner trucks 3034, 4958
OOIDA 677319
73's K5LDB
Highway Watch Participant, Truckerbuddy
EO Forum Moderator 1+ Years of Service
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Support the entire Constitution, not just the parts you like.

 

[dhalltoyo]

Anybody using Stanadyne Performance Additive? The web info indicates that its a GM approved additive.

Ran back from Florida last week. The Duramax seems to maintain consistent fuel milage regardless of the speed. I ran a few hours at 70+ and it didn't phase the economy.

Third generation engine has lower compression, so it turns over very easy. Runs quiet (well, as far as diesels are concerned). My brother has a Ford dually that pulls his 35' fifth wheel camper. Now that engine is very loud! He rode in a new Chevy truck on the jobsite and he couldn't believe how quiet the Duramax is compared to other engines. Of course, pickups do have more distance from cab to engine and the firewall soundproofing is thicker too.

GM wanted to put the Allison tranny in the van, but they couldn't reconfigure in time for production; so the van has a beefed up Yipsilanti Hydramatic transmission. Hot shoters are rough on trannys because pulling a trailer adds a different stress dimension. GM went to the Allison in the pick ups to offset the high wear factors of those who tow. Only time will tell if cargo loads will have a negative impact on the Duramax/Hydramatic combo. I haven't heard anything negative yet, but keep an eye out for 2007's that might have the Allison in them.

They did put a two-stage fuel filter system on board. The combo gives you a 15,000 mile range.

PS. The 2006 trannys use Dextron IV fluid. I talked with a service tech in Florida and he didn't even have any on the shelf. Had I not mentioned it to him, he might have topped me off with Dextron III. There is so little communication between the manufacturers and the dealers! Owners need to speak to every service tech BEFORE he touches the van! Everybody needs to be on the same page and I review everything that I want done BEFORE I hand over my keys. Oh, by the way, 1 bottle of Dextron IV is $13.95. Ouch! I sure hope the price comes down before I do a tranny flush.

 

[greg334]

Stanadyne Performance Additive – I use it. Actually I have had so much left over from my 6.2 days that I naturally put it in the tank. I need to go out and buy some more, running low. Yes it is GM approved and so is Racor additive.

I drove both an Alison/duramax and hydramatic/duramax van a while back; I liked the Alison a lot, it had a big lump in the floor where the trans sat. The story I got was the sheet metal needed to be shaped to fit the height of the transmission and some frame modification need to be done to the entire line to keep production cost down before it goes into production, you apparently can’t shrink the Alison enough. I have not talked to anyone about it since but I assume it would be a great thing if they get it together.