UPDATE: Two months, 14,500 miles

[markrinker]

Day #1 in service was an exceptionally long one, with only one short leg of the 880 mile trip unloaded. Trailer weighs 4500#, first cargo (steel/wood) weighed about 6000#, second was a 2000 Silverado (5800#?) with a fair amount of wind resistance from sitting backwards on the trailer.

~12 mpg for the day - secondary highways at 65mph, freeway at 72mph. I like the downshifting/engine braking feature of the Allison. Also the tow/haul shift points are perfect, just tons of smooth consistant power on tap. Way better than the 6.5/4L80E even with all the mods.

My 6.5 or 6.0 gas would have averaged about 8-9 mpg for this trip, based on past experiences. Saved ~$70 in fuel, day one.

My wife and I will be towing the boat to Lake Superior this weekend and back. It weighs 6800# full of fuel - will be interesting to see how it pulls and stops with the surge brakes.

Lovin' the DMax so far. Its gonna be hard not to want to mod it though...MORE POWER!!!

[ 09-26-2005, 03:07 PM: Message edited by: Mark Rinker ]

[Kennedy]

Change your engine oil. I also suggest the first fuel filter at 3-5k.

[markrinker]

I had planned to do the oil next week - will have about 1500 miles on it then. No time today, my wife is already &^%$(* about our late start as she took the day off...

JK would you go synthetic from the get-go, or more breakin time on conventional?

[JD Diesel]

I have always waited until I had 10000 miles on my trucks. cars. JD :D

[Kennedy]

Synthetic depends when you plan to change it next. I like to get the trash flushed out first so short term drain intervals are not practical with the cost of synthetic. I waited till I had 4 changes and my bypass installed before switching my 2005. I kinda got sidetracked or I'd have done it sooner. I changed around 85, 325, and 3k. At 5k I installed the bypass and lost track until 10k when I switched to Delvac 1. I've sampled every change, and 5k quick sample but haven't sent the 5k and 10k bottles in yet. I'll probably go to 20k for next change unless I get on the dyno and soot it up a bunch before then...

[markrinker]

Okay, JK I thought better of my priorities and stopped in for an oil change before leaving - 9XX showing on the odometer.

Averaged only 10.5 for the trip, hilly and pulling the boat which seems to pull harder for its weight than any other load I have come across. Also, my foot was bit heavy because we were running 'behind schedule'...according to the wife. (What is a vacation with a schedule??)

[markrinker]

8 days old and 3200 miles on the odometer, the truck delivered a 300lb pallette of parts without the trailer. Two full sized adults, cargo, and an empty drive home yielded 300 miles on 1/2 tank. Filled it up..14.9 gallons.

20mpg. WOW. (With my 6.5s and gasser 6,0 I start hunting for fuel between 240-260 miles on the trip odometer!!!

Woo-hooo!!!

[Kennedy]

300# or 3000#?

http://www.kennedydiesel.com/photogal/images/3k%20Load.jpg

[markrinker]

If you are referring to the picture, I would guess 300#, as 3000# would be putting more of a squat on the springs for sure - unless you have overloads, airbags, or a timbren block in place.

[Kennedy]

That's about 3k (5 6.5 cores) in the bed. No bags, just my extra leaf. All the way from Loyal WI to Sumas WA like that. We did NOT get 20 mpg...

I misread your post. I thought your 300# skid was typo, but then I read 14.9 gallons, not mpg...

[markrinker]

Two weeks in service and 6,100 towing miles on the odometer so far. I would estimate <500 without a trailer.

Loaded and unloaded trailer average has increased to nearly 14.

Another interesting factor is my new driver has a lighter foot, and is paid by the hour, not by the mile. He consistantly gets better mileage than me in the same truck with the same loads.

Rapid acceleration KILLS fuel mileage, even if you aren't overrevving. His method is to try to maintain 2000 rpm during acceleration, but never higher than that. I see 2300-2500 alot during acceleration.

Just a thought for those of you trying to get more mileage out of your LLY.

[markrinker]

The threads new title says it all.

Changed oil at 1,000 with conventional.
Changed oil at 6,500 to Mobil synthetic 5W30.
Changed rear diff at this time - synthetic.

Fuel filter and Allison spin-on filter next.

Love this truck. Love the money its saving me daily in fuel, mostly.

[jbplock]

Originally posted by Mark Rinker:
Changed oil at 6,500 to Mobil synthetic 5W30.Mark,

Just curious ... what type of Mobil 5w30 synthetic are you using? The two CI-4 diesel rated Mobil synthetics I'm familiar with are Delvac-1 and Mobil-1 Truck and SUV - both are 5w40.

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[markrinker]

Delvac.

[rjschoolcraft]

Probably ought to use CI rated oil.

[Jim Brzozowski]

Mark, its so good to hear good things instead of complaints. Keep it up. By the way the guys are right it should be 5w-40.

[markrinker]

My bad - typo and didn't read thoroughly.

Mobil Delvac 5W40 synthetic is what was recommended by my mechanic and what I am currently running.

RJ - what am I missing by running Mobil Delvac vs. Truck and SUV blend? Is Delvac not CI rated? If so, what does this mean?

[jbplock]

Mark,

Delvac-1 and M1 T&SUV are nearly identical. D1 was enhanced to meet the latest CI-4+ spec. Both meet CI-4 and the Duramax doesn't require CI-4+ .. just CI-4 (not sure about the 06's)... I was using D1 but have since switched to M1 T&SUV from Wal-Mart at $3.74 per quart...

See Engine Oil (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=008529) for some more info ...

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[rjschoolcraft]

Originally posted by Mark Rinker:
RJ - what am I missing by running Mobil Delvac vs. Truck and SUV blend? Is Delvac not CI rated? If so, what does this mean? Nothing... You had stated 5w-30 and I know of no 5w-30 that is CI rated. The Delvac 5w-40 is, so everything is cool. The CI rating is specifically for Diesels and pertains to soot control and other parameters important for Diesel engines.

[More Power]

Unless I missed it in another thread, you should change the rear diff synthetic lube. Recommendations are 500 towing miles or 10K light-duty miles for the first service.

Expect quite a bit of metal appearing on the magnets at the first service. Some (or most) of it is due to left over manufacturing debris, and some of it is due to break-in.

Jim

[markrinker]

Rear diff was done at 6,500 with synthetic gear lube. Tech never mentioned any residue on the plug. Wish I had thought to look.

I plan to keep updating this same thread, changing the original title each time to mark off the accelerated miles this towing vehicle will see. If business stays strong, it may see 60-80K towing miles in the first year on the road.

[markrinker]

12,000 miles fuel and external trans filters at stealership - $130.09. OUCH!

[markrinker]

14,500 miles, truck is three days shy of two months old.

Changed oil (8,000 miles on this change) - Delvac 5W40 synthetic and new filter. New OEM air filter as well - way overdue it was full of sand and BEES of all things. Will change more often for sure. Restriction gauge had barely moved - was nowhere near red zone.

Hailstorm yielded one visible dent in the middle of the hood where I have to stare at it all day long. Must call Paintless Dent guy...

[ 09-26-2005, 03:14 PM: Message edited by: Mark Rinker ]

[LanduytG]

Glad to see you are getting a lot of trouble free miles on her. I feel that the filter minders are a waste. Anytime I ever tried to wait for it to get into the red it was way over do. I never look at them any more.

Greg

[mark45678]

Mark a fw key things you can try to pick up a few mpg..... this is what I have found over the last few months of fuel cost being twice what they should be. turn the ac off if poss, keep your highway speeds under 72 mph, if you can draft any large car or truck you will see AVERAGE mpg in the high 19 teens! Ihave a lead foot and drive with juice set on level 3 all the time , my lly truck has 62K on it now . I almost have never had better then a 16 mpg average up to the last 3 months.... :eek:

[James T. Little]

Has anyone tried adding 3 oz. acetone to 10 gallons to increase fuel mileage?

[jbplock]

Originally posted by James T. Little:
Has anyone tried adding 3 oz. acetone to 10 gallons to increase fuel mileage? See adding acetone to Diesel could increase fuel economy..?? (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=008588)

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