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We (church)are looking for a new 25 passenger church bus. A F450 gas engine chassis bus was submitted to a vote tonight. I questioned the gas engine in that large of a bus. We use it weekly for in town trips and occasionally for a longer trip. We take one each year to Andrews, North Carolina to SWO and it is challenged by the hills of Tennessee. The gas engine would be the V10. The V10 is good(BAD) for low single digits in a chassis this size.
I know there are issues with the 6.0 diesel and Ford is going to discontinue it. GM chassis would be o.k.

We got 2 prices and one place from Kankakee, IL offered us $3000 for our trade-in which is a 96 model with 60,000 miles on it. The other place offered $12,000.


Does anyone have any experience with F450 size chassis in a 25 passenger bus?


Opinions for mileage + life for gas versus diesel?

This is a good thread. I didn't know how "bus unaware" I was until I looked around for available options.
The only 25 passenger buses I am seeing on a GM chassis are those using the Chevy 4500 frame (commercial truck). And there seem to be plenty available with the 8100 V8 Vortec engine. Like the Ford, it will leave you thinking someone drilled a 1/4" hole in the bottom of the fuel tank. The other engine I see in these GM-based buses is the 6.6L Duramax. That is a valid possibility, as the engine has been around a while and I haven't heard any horror stories about it. Nothing more than the usual "crappy fuel -> clogged filter" diesel stories. There are a few Duramax owners contributing here at CleanMPG and they may be able to relay personal experience.

This is a sample bus I found on one of the searches - the merchant appears to be based in Colorado.
http://www.daveycoach.com/product_info.php?manufacturers_id=&products_id=695
It's a 26-30 passenger, based on a movable luggage wall. I figured I'd add the link here to give others a visual of the kind of bus under consideration.

There are a few Duramax owners contributing here at CleanMPG and they may be able to relay personal experience.

I'm one of them.

Mileage and life will both be far better for diesel vs. gas, but there will be something like an $8k premium (new) for the diesel. Whether that's worth it or not depends on how many miles you expect to put on it a year and how long you'll own it. If it's just in town runs a couple times a week, I'd stick with gas (as much as I love diesel). If you put on 5-10k a year or more, the payoff for diesel may be pretty good.

It's tough to get good mpg numbers for anything bigger than a light truck, but in the heavy duty pickup world, it's fairly common to see ~ 9-12 mpg gas and 14-21 mpg diesel - both with light loads. I think I've heard medium duty diesel trucks tend to get mileage in the high single digits. 5mpg is common for heavy duty diesel trucks (i.e. semis), so a medium duty should do better than that. Hopefully this and a few google searches should get you some workable numbers for determining the payoff.

Another thing to consider is that diesel emissions regulations are forcing technology changes, some of which have a negative impact on fuel economy, reliability/durability, and cost. Have you considered a used diesel? Something prior to 2007 emissions would be my vote. GM's LBZ (2006-early 2007, I think) duramax is highly regarded on the duramax forums. The last few emissions hurdles have been in 2001, 2004, and 2007, and the next one is 2010. 2004 brought us EGR (not a good thing, but hasn't been horrible). 2007 brought DPF's. These added a bunch of cost and a mpg hit. I haven't heard of any serious horror stories with the 2007+ diesels, but they haven't been on the road that long either. 2010 emissions will (for most manufacturers) mean that they need urea. I believe the dodge/cummins commercial chassis already have a urea system in them. Urea actually provides an mpg improvement over competing technologies that meet the same emissions, but its another fluid to top off.

I know the Ford 6.0 and 6.4 diesels had their share of issues, but I don't know them enough to comment on which years had the most trouble. I believe Ford is working on their own diesel engine now, but I don't know when it will be available. In pickups, the general consensus I've heard is that the duramax and cummins tend to be the mileage leaders, with the powerstrokes a bit behind.

Thanks Pauli! Our other bus is a 96 model with 60,000 miles. So around 5000 per year is the average.
You are right about the diesel premium. The prices I found last night were $60-70,000+ for the diesel versions and $52,000 to $55,000 for the gas. I was worried about the gas reliability versus the diesel, but with the minimal amount of miles driven. I'm not sure it would matter.

I just realized that I made the (probably wrong) assumption that small busses get the same engine options as large pickups. I forgot that medium duty trucks have more than just the big2.5 to choose from. I know there's a larger (7.8L I6) duramax, some CAT engines, maybe a few detriots and cummins, and some truck companies have their own diesels.

Who's out there in the small bus world? Is there both ground-up builders, and those that start with a chassis from somebody else? What engine options are out there?

Who's out there in the small bus world? Is there both ground-up builders, and those that start with a chassis from somebody else? What engine options are out there?

The bus type that msirach's church is looking at is usually a cutaway chassis type. The bus manufactuers use heavy light duty chassis (like Ford's F/E450) or light medium duty chassis (like GM's 4500 or 5500, or IH 3800). Ford and GM offer both gas and diesel (same offerings as in pu's), IH just diesel.

I agree with the assessment to stick with gas. Not enough miles to justify added expense of diesel. And I have a hunch that predominately short trips would be brutal on a modern diesel's emissions systems.

I would focus on the chassis. The E450 maxes out at about 14500 GVWR. When going to a real medium duty chassis, the minimum GVWR is about 19000. Bus manufacturers will put a 25 passenger body on either size chassis. The fact that they go up to medium duty tells me they know that the E450 is a tad light for 25 passengers. The bus may be overloaded if the passengers are "average" sized. Not bad if restricted to city/low speed driving. But put 25 passengers PLUS their luggage on a high speed road trip, and the driver will need to be careful.

Is the old bus a F/E450 or equivalent? If so, then don't worry. But if it was a heavier chassis, the church may be unhappy with the smaller chassis.

As long as the driver is patient, a gas engine will do fine. Its the trying to keep a constant 70 mph in a headwind that kills engines.

Keith

Thanks Keith. That's pretty much what I have come up with. I talked to the owner of a dealership today that was genuinely concerned with customer satisfaction. He answered my technical questions without hesitation as well as adding candid detail. With the small amount of miles and several thousand dollar diesel package premium, it would take many miles of a couple of miles per gallon fuel savings to offset the initial cost. He estimated 8mpg so that gives me a goal this summer on a 450 mile trip to set the dual scangauges up and see how much the 8 mpg can be exceeded. I took the tires up to the 90 psi sidewall last year and the 96 Power Stroke pulled 11mpg (without me driving.) We have a box trailer that pulls the luggage and tools so it's strictly passengers on the bus.