I have a 2004 40 ft diesel pusher with a cat c7 rated at 330 hp. I am not sure what the difference is in this engine when compared to the previous years pre c7 cat 7.2 liter engines. Does anyone know what differences are? I have heard that part of the difference is that the epa required cat to reduce the timing to reduce n02 emissions. Reducing timing would I think reduce mileage. Does anyone know if this is true and has anyone had both engines for comparison?
Here is what I know... the C7 is an emmissions engine... meaning they did something (not sure what) to keep the tailpipe output a little "nicer"
I have a CAT 3126 which is a 2002 and is the same basic engine as the C7.
I looked at a 2004 Winnebago 36' DP with the C7 rated at 330HP and it's lifetime average MPG was about 7.5 from what I remember. It was used and very well cared for by the seller.
I bought a 2002 Itasca (Winnebago) 39' DP with the 3126 rated at 330HP and at first I was getting 7-8MPG but once I did a few upgrades and (mostly) adjusted my driving style now I'm getting 8-9MPG
So I'm curious to see others feedback and input on this topic.
SSSStefan
2009 Newmar AllStar 4154
2014 VW Passat TDI - toad!
Featherlite 28' Enclosed car hauler
1966 GTO - super cool car as seen on Driven1
First, most 2004 coaches do NOT have C7's. The C7 replaced the 3126 beginning with ENGINE PRODUCTION as of 1/1/04 to meet the new stiffer EPA emissions requirements.
Most chassis makers bought ahead as the earlier engines were less expensive (just as happened on 1/1/07 when the standards got even stricter).
Most C7's (not all) in RV applications were rated at 350 HP.
Best advice is to call the Caterpillar RV Hotline with your engine serial number: 877 777-3126.
And I do not know all the mechanical/electronic changes between 03 and 04 engines-- I suspect quite a lot of that information is proprietary. Few manufacturers will ever tell their competition how they controlled emissions. I suspect it was a number of things, not just one thing.