What Are The Actual Ratings (hp/tq) For An Lly In An 04.5 4500. Its An Allison By The Way. What Seems To Be Working Well For After Market Stuff On The 4500.

I got a 2005 4500, I believe the numbers are 325/610. I wasn't that impressed after have a cummins in my last dually. I had a dealer in phoenix put in a edge/attitude, it really woke up the engine. It has all the power my chipped cummins had but, with the cat in the exhaust I think there will be egt issues when pulling 20,000# in the hills. It has an allison 1000rugged duty series transmission which has heavier clutches then the pickups, so I was told.

I'm only getting 13 miles per gallon driving in the city. It sounds like you have to keep these things under 65mph to get any mileage at all. I only have 3000 miles on rig so far, hope it will improve. I'll be pulling a fifth wheel camper and motorcycle trailer that weigh 20,000# from Phoenix to Fargo,ND the end of March. Rear axle is 4.78, that will be a good test. Came down from Fargo with 2003 Dodge dually pulling same load. Did a great job, 10.5 miles per gallon at 65 miles an hour. Felt I needed bigger truck and brakes. I'll post the results when I get home.

That sounds good. I had a 99.5 PS F350, 01 D/A 3500, then an 04 HO Cummins 3500. They were all turned up alittle with different products. I know the 4500 will be quite a bit heavier especially with a 14' box but I was hoping for it to still feel strong. What have been the most succeful upgrades on these 4500. Again I know whats out there but I want to know what you guys like. Can anyone back up cropdustts ##s.

I was always under the impression the 45+5500's still used the 300/520 ratings.

Yeah... this is what I mean. Anyone nearly positive on the ratings?? This seems like alot off speculation. Not that it really matters.

Not sure on the ratings but.......the heat issues due to the exhaust can easily be remedied by goin to aftermarket. The other thing.....check out tts and there tow tune for your rig. 311 hp. at the wheels and sounds like great power. Mcrat should be able to tell you more......do a search for lly tts tow tune. If it were me trying to make a great tow only rig this is where I would start.

here is your answer straight from GM. http://www.chevrolet.com/mediumduty/kodiak/c4500/specifications/
It looks like the Dmax comes in two different configurations in the 4500 series.
Look under the engine catergory.

Do you ever feel like maybe even the manufactures do not give you all the facts straight

Looks to me like they're using the 3006hp 520tq version!!!

Seriously....I really think they still use the 300hp 520tq on the MD's.

I haven't heard anything said or written to say otherwise.

I want one of the 3006hp models, funny thing is someone out there is trying every power adder ever made to try and get 3006 hp.

On these commercial-grade trucks, changing the power-plant did not change the HP/TQ rating because the other components were not tested with higher power outputs. That may have to wait until model redesign, in order to get a higher rating certification for emmissions reasons.

It has to do with cost of re-engineering. Other mfgs have been known to federally certify with higher rated power than the production trucks, in order to have future flexibility, but as this was the first of its kind for GM, no higher rated power plants were available at the time of certification.

We may see some very sweet numbers in the C4/C5 trucks in 2007-8 time frame, when they are up for redesign, so hang in there folks. DMAX has gotten over 600 HP and 1000 TQ out of these engines already, which would facilitate the General getting certification for stronger motors.

RF