mileage chips for cummins diesel, allegro bus

[davidnmoore]

I have a 2000 allegro bus with 330 hp cummins 8.3 diesel. gets right now about 8 miles per gallon. have you or do you know anybody who has put in a aftermarket chip to improve horsepower and mileage, please advise.david n moore

[Mr_D]

If something like that actually worked Cummins would know about it and have already done it!
8mpg is about right for a an ISC. We have a Banks kit but I don't expect any great mileage increase, the extra power is nice though!!!!

[spike45]

Changing the ECM "chip" will violate the EPA emissions certification on the engine. There are chips available but they increase fuel delivery and alter injection timing. More power and in some cases less fuel consumption due to advancing the timing. Both can get expensive if you have to have an emission test and fail due to alterations. Money will change hands....from yours to the fine and penalties you pay EPA. Generally, increasing fuel delivery and/or timing advancement will change the engine air flow requirements. The standard MH air cleaner seems to be the Farr Ecolite. They are pretty limited now. They have little reserve air flow ability. It is not easy to change the air cleaner system to a larger higher flow capacity air filter housing on any MH.

[Gary RVRoamer]

It may be possible to tune a chip to provide slightly different performance parameters and still stay legal, but don't expect any mpg boost. There is no magic bullet - all the chip can do is trade performance in one scenario for something a bit better in another scenario. Fuel consumption is dictated by the horsepower needed to move your rig down the road, which is probably much less than its power peak anyway. Chipping it isn't going to alter that number any.

Now if it's more hp you want, there is probably something that can be done. Cummins knows how to make that same engine a 350, for example. But the fuel economy doesn't go up any.

[ua40j]

I had a 454 Chevy engine in an older Dolphin. The doghouse was hot and the coach was a dog. Including mileage that never was better than 6.5mpg.

I replaced the air intake with a Stinger type air inlet/cooler and I also replaced the stock muffler with a FlowMaster. Wow what a difference. Heat went away, noise moved to the rear of the coach, and I got a .5mpg difference for about $550 invested.

On our current 2002 coach with it's ISC 350, I couldn't find a replacement for the Farr Ecolite that I was willing to install. I haven't talked myself into spending $$$$ on a Banks system and I don't want to do K&N just yet. But I did replace the stock muffler with a performance muffler from MBRP and installed a new Farr Ecolite. Again....a big difference. The coach literally leaps off the line at stop signs for at least the first 50 feet (a little diesel humor here), it definitely runs cooler (rarely goes above 185degrees), it's faster on on-ramps, and I improved about .5mpg. Cost was about $250.

The MBRP M2050 is a wide open, flow through muffler that's a little throaty when you floor it. But my wife who walks next to the engine when we're backing up or hooking up the toad didn't find it objectionable. At full throttle going under an overpass, you sound like a cowboy trucker, but it's not bad.

I worked at Cummins in the Electronic Tools department and I know that all service tools look for chip and ECM changes. If my coach was under warranty, I would not chip it. I didn't want to get into a fight with the manufacturer if I needed warranty work. Out of warranty, not that big of a deal. However, as mentioned, nothing is free. Most power gains cost fuel. Timing changes can do somethings better, but as noted, if Cummins could eek out any mpg improvements, they would have done it. Fuel economy IS a big deal to all the engine manufacturers.

Just my .02 worth.

[Mr_D]

Quote:

Originally Posted by ua40j If my coach was under warranty, I would not chip it. I didn't want to get into a fight with the manufacturer if I needed warranty work. Out of warranty, not that big of a deal.

Exactly why I waited till mine was out of warranty before installing the Banks kit even though I knew the Magnusson-Moss act gives some protection from a manufacturer making false claims about add ons. (Dodge is well known for voiding warranties for modifications then making the customer prove it's not the modifications fault, just the opposite of the law)

[Mr_D]

Quote:

Originally Posted by Gary RVRoamer It may be possible to tune a chip to provide slightly different performance parameters and still stay legal, but don't expect any mpg boost.

We have EPA tests for diesels here, the ISC with Banks kit easily passes it, but I don't and never did expect a MPG increase.
Even with a new filter the filter minder shows 15 since I'm getting 34-35 psi boost rather than 24-25 psi as stock. Would NOT be easy to modify the intake plumbing and CAC to a larger size.