Diesel advantages over gas

[Dallas Baillio]

In reading ads for used BF's I see that a diesel sells for more than a comparable gas engine model. I don't see this as an advantage since a new diesel cost more to begin with. A used Lexus will cost more than a comparable used Camry.

So, what are the real advantages of a diesel?

Let's stick to facts that can be verified.

I know I can do a web search and find answers, but I would like to hear from BF owners and limit our discussion only to diesel vs gas in BF's.

Here we go! Post those responses. Those who rarely post please join in.

[montir]

In a word, the advantage is power.

We live in Colorado and routinely travel over mountain passes that reach 11,000 feet and camp at elevations of 10,000 feet or close to that.

We previously had a Lazy Daze 27’ unit on an E-450 chassis. It had a GVWR of 14,500 lb. and a GCWR of 20,000 lb. with a hitch rating of 4,000 lb. It had the V-10 Gas engine. According to Ford the towing capacity was reduced by a certain percentage for every 1,000 feet in elevation.(I don’t remember the exact amount). We towed a Honda CR-V that weighs 3,500 lb. When towing the Honda up a 7º mountain pass I was lucky to be able to maintain 35 mph. When eastbound on Vail pass I frequently got stuck behind a semi that could only maintain 25 mph. because the Ford did not have the power to pass without creating a really long line of angry drivers behind me. On one occasion when eastbound on Wolf Creek pass towing the Honda we got down to 10 mph. before we got to the top and I was wondering if it would stall before we got to the top.

With our Born Free on the F-550 Diesel 4X4 chassis it is a whole different world. The F-550 has a GVWR of 18,000 lb. and a GCWR of 26,000 lb. We tow the same Honda and are always well below the GCWR. With it we travel over the mountain passes at just about any speed we want to and I usually hold it to about 55 mph on the freeway passes. It could go faster but would use a lot more fuel. When not climbing a mountain pass it is a challenge to keep the speed down to 65 mph. as required by Honda and I frequently use the cruise control to keep from going too fast.

With the E-450 we averaged 8 MPG. With the F-550 we average between 10.5 and 11.5 MPG.

The downside to diesel engines include: several thousand dollars more to buy, maintenance costs more (they hold over 3 gallons of oil and filters are larger and more expensive), diesel fuel starts to gel at about 20º F. In cold weather I always add anti-gel to the fuel tanks unless I am certain that they contain the proper mixture of #1 and #2 diesel.

[whemme]

Monti,

I agree that a diesel has more hill climbing torque, not necessarily more power.

I have a much different experience with the hill climbing ability of my 2002 Born Free 26' RSB coach with the 305 HP V10 gas engine pulling a 3400 lb toad. I am currently on my 13th trip out west in my Born Free pulling up many 6% grades on interstates I-40, I-15, and I-10 out here in the states of NM, AZ, NV and CA.

By the way, interstate hills are posted in % not in degrees. I have always been able to climb those 6% hills at 55 mph in 2nd gear running the engine up to 4500 rpm. The Triton V10 is an overhead cam engine designed to rev and it will easily rev up to 4500 rpm if you can stand the resulting roar. I usually pull up those 6% hills at 45 to 50 mph but have done it at 55 mph but it is loud. Don't understand why you were limited to 35 mph climb speeds.

[montir]

Bill,

Yes, I didn't proofread closely enough about degrees vs percent. I hate it when I miss those things!

The way I finally settled on climbing hills with the Lazy Daze was to keep the RPM at 4,000 and let the transmission decide how fast it would go. Yes, it was LOUD and I don't think I ever attempted to keep it at 4,500 RPM. The grades I encountered most often were on I-70 and I-80 which tend to be longer than the ones I have encountered on I-15 and I-10. I never had problems with transmission temperatures but I know others who did (or at least saw them go high enough to worry about it).

Technically you are correct that it is torque where the diesel shines but when you are sitting in the driver seat it feels like power and I have no desire to ever go back to a gas V-10 motor home after driving 2 diesels. Actually, we expect the current Born Free to be our last RV anyway.

Yes, this diesel 4X4 cost a whole lot more than getting the Triumph on a E-450 chassis but the performance difference makes it a whole different driving experience.

[John S.]

Monti, your experience is why I ordered mine on the 5500 diesel and with a diesel generator there is no ethanol to varnish the carb too. I had the 24 rear bath on the E450 and it would scream up hills and I own a dodge pickup and pulled a trailer so the weight would be the same and it just walked up the same hills as easy as you like. There is no substitute for low end torque or the flat curve on the coaches but I need my coach someday to test it out.

[Dallas Baillio]

So far we have one basic fact based on experience. A BF diesel has more pulling power on hills.

Anyone else want to share additional facts?

[deshet]

Diesel engines are made to last longer (larger internal components) most RVs don't get used enough for this to matter but they are built for longevity and low maintenance.

Diesels require less maintenance (no tune ups or spark plugs) 10,000 and sometimes up to 40,000 mile oil changes (larger diesels).
Diesel can be modified to produce large amounts of power while burning less fuel.
Diesel's get better MPG doing the same work...this adds up on the business side of commercial diesel
The 7.3 diesel is one of the best medium duty diesel built. (emissions have hurt most new diesel engines but legal kits are available to help newer diesel).
Gas engines are found in entry level RVs as a way to keep the prices down.
The highest quality RVs and Buses are always diesel powered.
Until recently diesel fuel a (bi-product of refining gasoline) was cheaper worldwide. In the USA extra taxes drive up the price of diesel. If you do a lot of travel overseas diesel is cheaper on a global scale.
The maximum horsepower and torque are available much lower in the RPM band making the power more usable in normal driving conditions. (who cares if a gas engine makes 300hp at 5800 rpm when no one is turning that many rpm in an RV. Most diesels make peak power between 1800 and 2000 rpm, the normal driving range.
The engine doesn't work as hard to complete the same job.

Your question should be why would anyone pick gasoline over diesel and the primary reason is purchase cost.

Many diesels are built in a manner that an inframe rebuild can be done relatively easily and for low costs (sleeved engines).

Reading will not help you understand the differences you need to drive them and you will quickly see the difference.

Thanks,

[randallrae]

The attached article might be of interest.

20130311_CD_UMTRITCOFinalReport_dd2017.pdf

(784.15 KiB) Downloaded 328 times

[deshet]

The attached article might be of interest.

20130311_CD_UMTRITCOFinalReport_dd2017.pdf

I have reviewed most of the report. A decent amount of the information is accurate but keep in mind that it was written from a college students view point. The report has some erroneous information and has some information that is simple inaccurate especially for the larger diesel. I currently have 10 diesel powered vehicles ranging from an excursion, F450's, E450's, Freightliners, Cat, and internationals. The MPG for the diesel-powered trucks is inaccurate and manufacturers aren't required to provide this information. The article doesn't look beyond 3/4 ton pickups, which is almost pointless for most "Born Free" RVs are built on 1 ton and 1.5 ton frames. The majority of the vehicles in this report were German and all of the Volkswagon's have timing belts adding to the maintenance costs and costs of ownership. Heavy Duty/American-built diesel don't have timing belts and german Mercedes engines don't have timing belts. (only the audi and VW's)

Diesel isn't depreciated due to age at the same rate as gas. Check listings for a
1997 Dodge Ram 3500 gas vs diesel .........sometimes as much 300% increase in cost
2000 Ford F350 gas vs diesel..........at least valued at 100% more

Drive one and tow with one and you will understand the difference.

Thanks

[Dallas Baillio]

This thread has gone off the rails. I was looking for facts. montir says diesels cost more to maintain, deshet says less. Neither site supporting facts. I cannot control what is posted, but I can at this point say I see personal preference for a BF diesel as the determining factor, not any overwhelming body of evidence by any means.

[John S.]

I ordered a diesel for longevity and the fact I can get a diesel generator as well. I had a 24 foot rear bath with the v10 and a dodge diesel pickup. Oil changes are a bit further apart but you use more oil. No double spark plugs or coils to change. The maintainence costs between the pickup and my V10 were about the same. The fuel costs differed a bit and I could not match those up but the 24 foot gas Born Free got the same mileage as my 42foot Foretravel. Drivability is about the same but the low end grunt goes to the diesel. There are haulers with the 6.7L truck at 300-500k miles and it I see not unusual but no v10 I know will last that long. Also the diesel has an exhaust break on it and the v10 I had only downshifted and held speed if I put it in tow haul mode. I find it much easier to drive in the mountains as well as the diesel just works without screaming.

[shilohdad]

I am somewhat loath to join this conversation, but here it goes. The main argument for diesel seems to be that the engine lasts longer and provides more torque at low RPM, letting you navigate mountainous areas more readily without having the engine screaming at you.

OK. But for those of us who don't travel extensively in the mountainous west, the extra torque doesn't do anything for us. As for lasting into the mid 100 thousand miles, how many of us keep our coaches that long? And, if we did, does the rest of the coach and its systems last that long? How much would it cost to maintain the rest of the coach and its systems as long as the diesel engine lasts?

If I lived in Colorado or Montana, or traveled extensively in those areas, I might have contemplated buying diesel coaches. Since I do most of my traveling east of those areas, the extra torque is not that much of an issue. Even when I have traveled in those areas, the limited time I spent there did not make me want to spend the extra $$$ for a coach that let me climb those mountains at 55 or 65 or 75 MPH. I just downshifted and went 45 MPH.

Getting off my soap box now.

All opinions are Joe's, not necessarily Lucinda's, nor even Tonto's nor Meadow's, neither of whom have traveled through the western mountains with us, although neither Morpho nor Shiloh seemed to be bothered by the engine noise when we traveled there.

[John S.]

I agree that people travel differently. I sold my last coat at 186,000 miles this one I want to keep till I hit 300k at least. That will be ten years or so for me. I find it better in the rolling hills of the east and the addition of a diesel tensest that's runs at 1800 rpm instead of 3600 in the gas or propane version is a benefit as well. It is a wash at the end if you consider the higher mile per gallon and the longevity and the ability to get a higher price when you sell. It I sold each their own and I have had two gas born frees but ordered this one diesel with an extra fuel tank and two alternators and I hope I beat the 8-9 mpg my 24 foot gas did and if it is the same I will be happy with the better ride and drivability.

[whemme]

John,

I assume you meant to say coach rather than coat. And I am not familiar with tensest with being an alternate name for a generator. I learn something new frequently on this forum.

[John S.]

I do hate autocorrect on the phone.