Gas or diesel in smaller MH?

[Gary - K7GLD]

Been looking at motorhomes in the 32 foot class - and about '95 vintage.



Seems the diesel powered versions typically run a good $5-6K bucks more than the gassers - the diesels are commonly the Cummins 5. 9 in the 230 HP range, gassers are a mix of Ford 460's or GM 454's. In the gassers, I lean towards the GM 454 due to what appears slightly better fuel economy.



And the MPG is one of the largest issues -in MH service, the difference in MPG between the diesels and gassers doesn't seem nearly as significant as it does in our usually more lightly loaded trucks - and we're talking a GVW of just under 20K for a MH in the class I am considering.



I figure a gasser MH in that class will be good for close to 10 MPG in average overall use, and a diesel perhaps a couple of MPG better - but certainly not enough in this service to justify the price difference I commonly see in used units.



Long range engine life for us is not a big issue, since it wouldn't be seeing many long-haul outings, mostly stuff withing a 600 mile radius - mostly less than that. Naturally, reliability IS an issue, and it seems the larger displacement gassers hold up reasonably well when treated decently and serviced properly.



Any ideas - is there any significant reasons in a case like mine to go another 25% in cost for a diesel? I can sure buy lots of gas for the $5K or so difference the diesels are going for!

 

[Gary - K7GLD]

HMMmm - I thought more in this forum might have experience or knowledgeable info in regards to the thread subject - no MH users out there with something to offer?

 

[WMonroe]

I have no motorhome experience, but the guy I work with has a 454 in his 3/4 ton chevy and he gets a consistent 8 mpg in normal driving. He is a very laid back (slow) driver. I don't know if this helps any but it is something to think about.

Will

 

[Gary - K7GLD]

I have no motorhome experience, but the guy I work with has a 454 in his 3/4 ton chevy and he gets a consistent 8 mpg in normal driving. He is a very laid back (slow) driver. I don't know if this helps any but it is something to think about.

Will

I believe the 454 GM gasser as used in the heavy trucks and MH's are setup and tuned as heavy-duty power - not as higher performance stuff as seen in passenger type power - they tend to be specially cammed, tuned and lower compression for more sustained power and lifespan - as well as better economy. At least that's my understanding - and my youngest son has a MH in the class we're looking at, and averages about 10 MPG even when towing a medium sized Ford sedan.



But I'm interested in whatever relevant input you guys might provide...

 

[SnoKing]

10MPG will be downhill. In a 32 footer, you can firgure on 6-8 MPG. SNOKING

 

[Gary - K7GLD]

10MPG will be downhill. In a 32 footer, you can firgure on 6-8 MPG. SNOKING

WELL, I base my GM 454 MH mileage on what our son actually gets with his MH of the same general size and GVW I'm looking at - and he gets close to 10 MPG in all around driving, and towing a Ford Probe sedan. He also lives here in Oregon, so usually travels in the same type locations we do.



Back in the '95 year range I'm looking at, the only commonly available gas engines were the Ford 460, or the GM 454, plus a few Chrysler 440's I wouldn't have in ANY vehicle - no V-10's I'm aware of - and the Cummins most commonly used was the same 5. 9 230 HP or so used in the same year Dodge trucks - although the Allison 6-speed automatic was also commonly available at that time as well - and is probably the main real advantage with diesel power.



As far as real world diesel fuel economy, I will sometimes see as low as 12-13 MPG with our '02 Dodge towing our 24 foot 5er - if I'm really pushing it, and that combo weighs in at slightly less than 14K GCVW. But of course, with my engine mods, the fuel consumption SHOULD go up if I get heavy on the pedal!



Of course, if I baby it, above 15 MPG is easy...



We're long-time 5th wheel RVers, so pretty familiar with all the hints and tricks of RV travel and camping - all that's really changed, is the need to also transport a fishing boat to some of the further away spots without having to take 2 tow vehicles.



As to pricing, a 30-32 foot MH like I've seen will run about $15K for a gasser, and as much as $22K for the same rig in diesel - quite a difference, when the power difference in those years wasn't all that great, and the diesel will usually only do a couple of MPG better than the gasser - and needs more expensive fuel to do it!



Like I said, I can buy LOTS of lower cost gasoline for the $5k - $7K difference in MH price, diesel vs gas. Added to that, is the fact that here in our "Golden years", our RVing travels are much closer to home than in the past, and most trips are usually well under a 200 mile radius.



With a larger and heavier MH up in the 36-40 foot range, and much heavier GVWR, the choice is easily diesel - but that doesn't necessarily seem to be the case in a 30 foot or so MH in the 18K GVWR range.



I don't mean to sound like my mind is already made up, I just need REAL-world info from folks with up-close experience between the 2 power choices, and taking my specific needs and goals in mind - do a half-dozen or so fishing trip per summer, with maybe a single longer 600 mile jaunt down to the kid's place in California REALLY justify the considerable extra expen$e of the diesel?

 

[Crazy Horse]

10MPG will be downhill. In a 32 footer, you can firgure on 6-8 MPG. SNOKING

Downhill is right! In ideal condtions you may pull 10 out of a 32'er. In real life driving you'll get 6-8 average. I used to sell motorhomes and have owned a few RV's myself. From my experience and input from customers and acquaintances the diesels will close to double the true estimated averages. Thats fitting the proper CID motor for the GVW rating. And, that's same driving conditions-vehicle weight-tire pressure,etc,etc.



My old Ford 460 did the same as my Dodge V-10 gasser with the same camper in the bed with same road rips; 6-8 mpg. I got 9. 2 once . With the same camper going into a 3500 Cummins in 2000 the average mpg was 13-14 mpg, same road trips. One year I drove the truck with the camper in the bed for approx 21,000 miles, it never got worse than 10 mpg bucking any headwind or pulling any mountain at any speed.



The main thing you will need to do is figure the worth of the investment. How much driving you will need to do to pay off the investment increase. Personally I like the feel of a diesel under me.

 

[MA2LA]

I have a coachman 29ft E-350 with the v10 witch i haven't had time to do anything with but the prior owner said it did between 10 to 12 mpg depending on speed and that was even towing a s-10 blazer. weather or not he full of it I'm not sure but others I have talked to gave similar numbers. And the v10 tows pretty well.

 

[SnoKing]

My friend has had two Class-C's with V10 and both got around 8 towing a small car. SNOKING

 

[Simplysmn]

Good friend had a 33 ft pusher with a cummin's and with a trailer and a tundra on trailer going back to and from OK city he averaged 13mpg doing 65 to 70 mph I would say the diesel is worth it if you plan on keeping it for a while I am sure it will pay for it's self rather quickly . JMO

 

[Skydiver]

My friend had a 2000 4x4 f-250 with the v-10 (free company fuel) 14-15 mpg.

It had 290,000 trouble free miles on it as it caught fire and burned to the ground. The truck sat on a construction site idleing almost all day every day.

I added this post because of the way his v-10 held up.

Get the diesel motor home,it will have better resale value.

 

[Gary - K7GLD]

My friend has had two Class-C's with V10 and both got around 8 towing a small car. SNOKING

have a coachman 29ft E-350 with the v10 witch i haven't had time to do anything with but the prior owner said it did between 10 to 12 mpg depending on speed and that was even towing a s-10 blazer.

My friend had a 2000 4x4 f-250 with the v-10 (free company fuel) 14-15 mpg.

Guys, I appreciate your comments, and assume they are offered as a MPG comparison between gassers and diesel power - but fact is, a later model V10 isn't even a choice here - the available choices are:



1. Ford 460 V8 gasser

2. GM 454 V8 gasser

3. Cummins or possibly GM 6. 5 diesel



And THAT'S about it in the year models ('95 or perhaps out to a '98) and price range we are looking at!



And for the record, my brother-in-law has a fairly late model 27 foot Winnebago class C gasser on a Ford chassis, powered by a V10, gets about 10 MPG, and that thing is so GUTLESS it starts shifting down in a 5 MPH headwind, or even if a slight rise in the road is in view! I suppose that would be livable in the relatively light use we would put on one, but that lack of power sure is disgusting. My truck/5er combo weighs the same as his, and I can absolutely run off and leave him in the hills! :-laf



I had hoped the older big block gassers were a bit more powerful, like the '76 Winnebago we had powered by a Dodge 440 - but man, what a gas hog, 5-6 MPG on a GOOD day, and that was bad enough even then with 98 cent a gallon premium gasoline that that 440 required!



No doubt about it, power comes with a price, and THAT becomes the issue I keep hammering on - and there seems no easy answer. We're all diesel-heads here, and it's natural for us to instantly assume and fall into the line of reasoning the that characteristics of diesel power will outweigh all other options - but that ain't necessarily so!



When you consider the available engine options and power in '95-'98 - both diesel and gasoline, realize the average annual mileage will be less that 5K miles and a 200 mile radius, and then the fact that a gasser will run about $15K (which IS important on a low use vehicle!), while that SAME MH in diesel power will run about $22K - the diesel vs gasser reality starts getting REAL muddy!



A little rapid math on potential fuel costs in this case - 5K miles per year, $3 a gallon for both gas and diesel (using what I consider most favorable conditions for the diesel!), at 9 MPG for the gasser, and 13 MPG for a similar diesel, the difference in annual fuel cost would be roughly $500. Not bad, but if I have to pay an extra $7k for that diesel power, it would take almost *15 years* to break even on relative cost - and I'm 71 years old! And remember, as far as power is concerned, the '95-'98 diesels weren't exactly powerhouses when pulling 18-20K GVW either!



I fully realize and acknowledge the bias we have here in favor of diesel power - and prefer it myself as long as other associated issues justify it - but in THIS case, it will likely boil down to which of the 2 possibilities shows up in the condition and price I feel is most attractive - whatever we get, if anything, will spend LOTS of time just sitting - and it's lots easier to "sit" $15K than it is $22K. :-laf



But thanks for all comments, both past, and any followups - all greatly appreciated!

 

[Grizzly]

Gary, I agree with what others are saying about the poor mileage large gas engine get with the size load your are proposing to haul. I also agree with the longer longevity of the diesel engine.



One thing no one has mentioned is the safety of a 5th wheel over a MH. In a 5th wheel you and your wife are in a safer heavy truck in case of a collision. In a MH you may have to deal with flying cabinets, appliances and other large items in case of a collision. MH are also constructed with thin wood or aluminum frame, which will croumple and crush easily. I subscribe to RV Consumer Group Price and Rating Guide. In it, they said to consider which brand of MH you are buying because some do not attach the cabinets and appliances very securely to the thin studs and thus can become a projectile in a collision. Think of it like putting an engine on a TT and driving it on the Interstate 65 mph with you right up front. RV Consumer Group rates all RV's back about 15 years. Also with a MH you may have to haul a small car behind you for local transportation, which creates for less fuel economy.



In my opinion, I think that the best and safest RV is a Dodge/Cummins and a well rated small (27' or less) 5th wheel with non Chinese, LT tires.

 

[Gary - K7GLD]

Gary, I agree with what others are saying about the poor mileage large gas engine get with the size load your are proposing to haul. I also agree with the longer longevity of the diesel engine.



One thing no one has mentioned is the safety of a 5th wheel over a MH. In a 5th wheel you and your wife are in a safer heavy truck in case of a collision. In a MH you may have to deal with flying cabinets, appliances and other large items in case of a collision. MH are also constructed with thin wood or aluminum frame, which will croumple and crush easily. I subscribe to RV Consumer Group Price and Rating Guide. In it, they said to consider which brand of MH you are buying because some do not attach the cabinets and appliances very securely to the thin studs and thus can become a projectile in a collision. Think of it like putting an engine on a TT and driving it on the Interstate 65 mph with you right up front. RV Consumer Group rates all RV's back about 15 years. Also with a MH you may have to haul a small car behind you for local transportation, which creates for less fuel economy.



In my opinion, I think that the best and safest RV is a Dodge/Cummins and a well rated small (27' or less) 5th wheel with non Chinese, LT tires.

All excellent and appreciated comments! Unfortunately, we already have a 5th wheel - love it, but the need to get BOTH the 5er AND a fishing boat to more distant locations without 2 tow vehicles is the problem!



I have found what MIGHT be a compromise solution - a 28 foot MH on a Isuzu chassis - uses a 4 cylinder diesel, and appears to be based on the drivetrain Isuzu uses in it's line of commercial delivery trucks and vans. HP is rated at 135, and torque at 225 - not much, but it is a smaller and lighter MH too - any comments from folks familiar with the Isuzu diesel setups back in about '94?

 

[klenger]

What about a slide-in camper on the CTD?

 

[Gary - K7GLD]

What about a slide-in camper on the CTD?

Too limiting in space - our 24 foot 5er is about as small as we'd want to go - plus I have an in-bed tool/fuel tank that prevents camper installation.

 

[SnoKing]

So, what the big deal about taking the second vehicle, you said that you are not going far, and you already own both vehicles. Launching the boat with a MH would not be that fun. My wife and I have done this a few times over the years - two vehicles. She gets to drive that way! SNOKING

 

[Gary - K7GLD]

So, what the big deal about taking the second vehicle, you said that you are not going far, and you already own both vehicles. Launching the boat with a MH would not be that fun. My wife and I have done this a few times over the years - two vehicles. She gets to drive that way! SNOKING

Reasonable question.



By "not far" as describing potential MH use, I've been pointing out that several destinations are about 200 miles away, and we might hit those a half-dozen times a year. That's not much in terms of long range travel in a MH, but IS a long way to also have to drive a second vehicle - especially when one of the major arguments in favor of a diesel powered MH revolves around potential MPG - and combined MPG if using 2 vehicles is pretty putrid!



THEN, there's the extra vehicle charge most CG's in this area charge for a second vehicle - and THAT space is often halfway around the CG...



I wouldn't try to launch a boat by backing down a ramp with a MH - for about $100, you can install wheels on the rear of a boat which allows it to be removed from the trailer out on the parking lot, and simply be wheeled into the water...



BUT, it's pretty hard to justify the extra expense of a MH - $15K is bad enough for a gasser - $22K for a diesel is even worse - especially for the relatively light use we probably would get outta one - but damn, I sure hate the necessity of 2 tow vehicles on some of those longer outings... :{

 

[SnoKing]

Reasonable question.



By "not far" as describing potential MH use, I've been pointing out that several destinations are about 200 miles away, and we might hit those a half-dozen times a year. That's not much in terms of long range travel in a MH, but IS a long way to also have to drive a second vehicle - especially when one of the major arguments in favor of a diesel powered MH revolves around potential MPG - and combined MPG if using 2 vehicles is pretty putrid!



THEN, there's the extra vehicle charge most CG's in this area charge for a second vehicle - and THAT space is often halfway around the CG...



I wouldn't try to launch a boat by backing down a ramp with a MH - for about $100, you can install wheels on the rear of a boat which allows it to be removed from the trailer out on the parking lot, and simply be wheeled into the water...



BUT, it's pretty hard to justify the extra expense of a MH - $15K is bad enough for a gasser - $22K for a diesel is even worse - especially for the relatively light use we probably would get outta one - but damn, I sure hate the necessity of 2 tow vehicles on some of those longer outings... :{

OK, so now we know the boat is not that big. So! Get one of those boats that folds flat and mount it on the side or under the 5er. Port-a-boat? You are good to go! SNOKING

 

[WMonroe]

What about towing the boat behind your 5er? I love seeing pictures of a CTD pulling doubles. :-laf

Will