'08 LMM towing update above 8,000 ft elevation.

JetA
05-26-2008, 01:54 PM
Well, 10,000+ miles on the truck and we towed our 11,000# fifth wheeler. We towed for over 2,100+ miles from the Arizona desert up to the Sierra Nevada mountains and into northern CA. We stopped at several places to camp for several nights at a time. We were atop at over 8,000' foot elevations. In fact, I believe we were closer to 9,000' once we got to the top of a mountain just outside of Independence, CA.

After a week up there, we headed north past Mamouth Lakes, CA. Man, talk about a steep steep grade going up Hiway 395 past Bishop, CA. Holy $h!T.

Anyway, the LMM performed beautifully. It really beat out my 2004 F-350 gas engine (work) truck. The towing comparisson between the two trucks can't even be compared. On second thought, yes it can. The Chevy Diesel won, my F350 gasser lost.

My average MPG's over the entire length of the trip was 13.2 MPG's. I really take it easy and never went over 55MPH while on level hiways.

Going up steep hills in the mountains was not a problem. The truck wanted to go faster if I allowed it to with the throttle. But, I didn't. I went through numerous "regens" as far as I could tell, but that was over a 4 week period of refueling and heavy towing. I considered it all "normal."

I used the Mobil "Delvac-1" ESP fully synthetic oil (5w-40) (API: CJ-4) and plan to send off a sample tomorrow for oil-analysis testing. I'll post the results. Also, I have zero "mods" done to the truck. It's bone stock. All of the emissions crap is left in tact. I have to leave everything "as is" due to the fact here in CA, we're being required to have diesels "smog checked" within the next 2 years! (F^#K!!!)

Final Conclusion: The LMM performed flawlessly. Even during hot 100F temps in the desert, the temp gauge remained in the "normal" range. In fact, it didn't really rise above 210F on the temp gauge. The Allison tranny temps stayed under 195F the entire time during the hot desert hill climbs too. Passing semi's and gas engined trucks with trailers up steep hills was down right FUN!

I think the nay-sayers about the LMM's just complain because they've not yet owned one, or they've moded their LMM's to where it caused problems. Just my own opinion.

jim87vette
05-26-2008, 08:05 PM
Glad to hear you had a good trip sounds like a success to me!Will have mine Wednesday and I can't stop thinking about it lol!

heoperator87
05-26-2008, 08:28 PM
Awesome! Makes me more anxious to pull.

RI Chevy Silveradoman
05-26-2008, 08:33 PM
Moved to the Towing Section. :)

BIGR
05-26-2008, 08:47 PM
Glad to hear your trip went well. Its nice to hear about reports like this and it only proves that much more that the Duramax is the king of towing.

BlackMariah
05-26-2008, 10:11 PM
Conway summit outside of Mono Lake - probably claimed its fair share of transmissions and brake rotors.
Thanks for all the good information. Hope you enjoyed the area.

I've had the same experience with towing mpg. Slowing down seems to be the key to getting 13+.