Diesel vs. Gas

That's true Gary, but what is inconclusive?

  Gas engines may last a long time in a MH, but it really is way too heavy for a gas engine , especially out west, and pulling a load.  At least out here, you don't even see many newer gas 3/4 T pick ups.
GM would only warranty my new engine for 12 Mo 12K miles because it was going in a MH, and if it was going in a PU it would have been  5 YR, 100,000 mikes.
  I say again,  gas MH's are for people who can't afford a diesel, like me.

max49 said:

That's true Gary, but what is inconclusive?

  Gas engines may last a long time in a MH, but it really is way too heavy for a gas engine , especially out west, and pulling a load.  At least out here, you don't even see many newer gas 3/4 T pick ups.
GM would only warranty my new engine for 12 Mo 12K miles because it was going in a MH, and if it was going in a PU it would have been  5 YR, 100,000 mikes.
  I say again,  gas MH's are for people who can't afford a diesel, like me.

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What were you doing when it threw a rod?

max49 said:

That's true Gary, but what is inconclusive?

  Gas engines may last a long time in a MH, but it really is way too heavy for a gas engine , especially out west, and pulling a load.  At least out here, you don't even see many newer gas 3/4 T pick ups.
GM would only warranty my new engine for 12 Mo 12K miles because it was going in a MH, and if it was going in a PU it would have been  5 YR, 100,000 mikes.
  I say again,  gas MH's are for people who can't afford a diesel, like me.

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NOPE, NOPE,NOPE,NOPE,NOPE,NOPE, that 8.1 coupled with Allison is a beautiful match. You just got a bad bullet, if I were the tech who worked on that rig I would not be able to sleep until I figured out what happened. These tech nowadays are parts changers. They really don't care what caused a certain problem, fix it and move on. I've seen your posts on the other RV site, man I want that engine in my garage so that I can dissect it. Gas engines have been doing plenty of work for many years, nothing wrong with them. Even on the hills they get the job done, slower than a DP, but it gets done.
J

max49 said:

That's true Gary, but what is inconclusive?

  Gas engines may last a long time in a MH, but it really is way too heavy for a gas engine , especially out west, and pulling a load.  At least out here, you don't even see many newer gas 3/4 T pick ups.
GM would only warranty my new engine for 12 Mo 12K miles because it was going in a MH, and if it was going in a PU it would have been  5 YR, 100,000 mikes.
  I say again,  gas MH's are for people who can't afford a diesel, like me.

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I agree that it's inconclusive.  One isolated failure out of the thousands of engines in the field does not create a compelling case for diesel vs. gas engined powered motorhomes.  There are some of us who could afford a diesel and just chose not to.  Not everyone thinks the same as everyone else - that is part of what makes this country great. ;D

34footer said:

NOPE, NOPE,NOPE,NOPE,NOPE,NOPE, that 8.1 coupled with Allison is a beautiful match. You just got a bad bullet, if I were the tech who worked on that rig I would not be able to sleep until I figured out what happened. These tech nowadays are parts changers. They really don't care what caused a certain problem, fix it and move on. I've seen your posts on the other RV site, man I want that engine in my garage so that I can dissect it. Gas engines have been doing plenty of work for many years, nothing wrong with them. Even on the hills they get the job done, slower than a DP, but it gets done.
J

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I'm not meaning to hurt any one's feeling; but,  if you've read 'the other site',  there may be more that I don't know of,  but my 8.1 was the 3rd failure on that site that I remember  and the 4th one is still current (Engine - Just Blew) and now has tranny oil leaking problems.  Check his picture of his oil pan, it looks identical to mine

As far as what I was doing when mine blew,  I don't know what you were hoping I would say, but I broke down in Georgetown CO on the approach to the Eisenhour tunnels, WB and it was the calm before the storm, a relatively flat section, I was going about 50-55 MPH in D at about 3000 RPM.     
I used to think they were bullet proof,  but now I kinda baby it.  My old engine ran perfect one second and was banging like crazy the next, no warning at all.
  I also would have liked to know what happened to the engine but I did'nt want to pay for the autopsy.  The shop said must have been a manufactiring defect.
  I suspect, but I don't know,  a valve dropped and the piston was banging it.  I had it towed but then the shop decided to drive it inside to work on it after they rehooked the drive shaft back up,  that is when (I suspect again)  the piston jammed into the valve, broke the  crankshaft, , spung and pushed the rod through the oil pan.  If any one has a different idea on what happened, I be interested in hearing it.

max49 said:

As far as what I was doing when mine blew,  I don't know what you were hoping I would say,

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Hey Max,

I wasn't hoping for anything, just curious. For it to happen rolling flat with nothing unusual going on seems suspect to me. That engine should not fail in that instance, which leads me to believe that it wasn't a load issue. If you were pulling a heavy towed on a steep incline on a very hot day with an RV full of folks... I might lean that direction. I am not familiar with the others you mentioned, but were they the same type engine close to the same year? I'd bet a dollar to a dime that the broke rod was made in china.

I would be very interested to know if the other engine started banging like mine did.  The most recent has a hole in the oil pan very, very similar to mine,  but some  people don't post "the details" on the forum, like I did.  The last MH was an '09 with the same engine and about 14,000 miles and the others were '04-'05 ish  with between 20 & 30,000 miles.
  My MH was on a fairly flat section of the Climb out of Denver when it blew, but it had been climbing for 6% for 20-30 miles and if it had'nt quit, it had another 5 or 6 miles of steep grade up to the tunnel.  I was pulling a 2 place, single axle trailer with 2 ATVs on it.
  My MH and most CO MHs have a tough life and  I'll admit, it had seen 5000 RPM several times while it was under warranty. In the last couple of years, I've tried to hold it no higher than 4600 RPM.  Now , that I know they may not hold together and  I know my new engine cost $14,000,  I am trying to keep it below 4100 RPM  so I will be climbing the mtns at 30 MPH instead of 36ish MPH.
  However, the other failures, that I heard of have come from back east and TX where the land is relatively flat.
I know of some 8.1s with 90,000 miles and I hope mine new one will last that long too;  I just think  the gas engine MHs are over worked and under powered for the load they have to carry.    But they are relatively affordable and cheaper to maintain.
  If Ford ever discontinues their V-10,  the only gasser left, it's going to be alot more expensive to get into a CL A

When we first started camping and taking vacations in our pull behind I pulled it with a 2004 Tahoe and it did a great job BUT every hill we came to the engine was running wide open and sounded like it was pulling it guts out,
There's two reasons we bought a DP, The first and biggest reason is to get the engine in back to alleviate the noise. The second reason is dependability.
But really to me it comes down to personal choice.

The article that was mentioned above states "A diesel Engine is more complicated than a Gas engine" is in error, a diesel engine is much simpler, No spark plugs, no ignition system and much more improtantly runs at a much slower speed. Yes the Gas engines are lasting more miles but most failures in a MH are from the high RPM that the engine must work at to climb those mountains. A lot of the gas engines are over rev'd when downshifting to slow down on the downside of a mountain. Because I have driven trucks with exhaust brakes, I keep my exhaust brake on all the time which really saves the service brakes. IMHO I believe the oil change intervals on a diesel help negate some of the higher maintenance costs associated with diesel. If you take it easy with a gas engine it may last 200,000 but I know truck fleets who consider 80,000 miles on a gas engine to be about the limit where as a diesel in the same size truck is normally scheduled for overhaul or disposal at 500,000miles + .  Talk to fleet operations at the rental companies such as Ryder.

gwcowgill said:

A lot of the gas engines are over rev'd when downshifting to slow down on the downside of a mountain.

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You should not have to downshift, the gear you go up in is the same gear to come down. Keep the revs at 3800-4000 and all will be alright.
J

As my sig suggests I am involved with busses and by extension diesels. I am employed as a garage supervisor in city transit with over 1100 busses in our fleet.
My previous vehicle was a 40 Ft. 5th wheel towed by a diesel dully pickup. When we decided to move up to a A class the question of gas or diesel came up and we looked at both for some time ( over a year). I finally decided on a gasser for purly economic reasons. Our bus fleet ( all diesel) runs Cummins and Detroit, and believe me they do break down. When they do, repair costs are astronomical. On the Cummins we do a lot of fuel system repairs and on the Detroits its complete engines ( crankshafts break and explode out the bottom) Both engines need turbos every 40000 Kilometers. Turbos cost more than a gas engine!!

I am happy to put up with a little less pulling power.  Bill

Busman2102 said:

Our bus fleet ( all diesel) runs Cummins and Detroit, and believe me they do break down. When they do, repair costs are astronomical. On the Cummins we do a lot of fuel system repairs and on the Detroits its complete engines ( crankshafts break and explode out the bottom) Both engines need turbos every 40000 Kilometers. Turbos cost more than a gas engine!!

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I have always been under the impression that "in general" the diesel powered over-the-road buses ran for 500k or more miles with very little repairs. My old 4104 had a 671DD and i was told them engines would go on forever. If I get a coach with a 8v71 how many trouble free miles should I be able to get?

I don't mean to hyjack the thread...

You should not have to downshift, the gear you go in is the same gear to come down. Keep the revs at 3800-4000 and all will be alright.
J
That is correct if people would adhere to it. I have replaced several engines that had been over revd by down shifting. Not all people have proper driving techniques. I was on the downside of a 6% grade in Maryland last year when I seen this very thing happen.  I seen a beautiful MH land on it's side in VA on I-77 because he locked the brakes up and lost control. Fortunately no one was hurt but sure was a shaken up driver and DW. I prefer the exhaust brakes of a diesel where I normally don't have to step on the brakes. Note: I prefer, others drive the gasser as it should be driven. BTW, the longer the stroke of the engine, the more more torque produced the less RPM they will tolerate.

gwcowgill said:

You should not have to downshift, the gear you go in is the same gear to come down. Keep the revs at 3800-4000 and all will be alright.
J
Note: I prefer, others drive the gasser as it should be driven. BTW, the longer the stroke of the engine, the more more torque produced the less RPM they will tolerate.

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....and since these engines peak around 4200 rpm anything more is just beating on a dying horse. You're climbing hills in 3rd with a 4.86-5.13 rear and the revs are heading for 5000 rpm for more than five miles, I'm surprised that more gasser cranks have not twisted. It may not break on the climb but you are doing damage and who knows if or when the end will come. Then people want to cry and blame
GM and Ford.
J

technique, technique, technique.

34footer said:

You should not have to downshift, the gear you go up in is the same gear to come down. Keep the revs at 3800-4000 and all will be alright.
J

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I don't understand this at all.  Our F350 does this down shifting automatically, point is that using the motor and it's compression is what saves the brakes and keeps the vehicle in control.  Why would the manufacture program the vehicle to down shift if it's not necessary?  Not sharp-shooting here, just trying to understand.

All automatics upshift and downshift automatically, but not always at the correct time. To get the most out of various rigs some manual shifting may be required.
Since mine is a 1988 with a 3spd trans I have to control things myself.
J

My Dodge 1500 5.7 hemi gas pulled our TT up and down 11,000 ft mountains in Western Colarado and didn't go over 3200 RPM. I had no problem keeping up with diesel MHs.  The thing is, one needs to understand the limits of their rig.  I don't overload my truck, I'm not in a race but never dropped below 35 mph on the climb except where tight turns dictated a slower speed.  While my rated towing capacity is 8200 lbs, my actual TT weighs 6300 lbs whjich provides a comfortable margin.

There is no standard right or wrong answer to the diesel vs. gas question.  We are all unique, have different requirements or standards.  If you like diesel or you like gas, do what makes you happy.

I have puller trailers with Dodge Ford and Chevy. I have pulled with a 350 ci , 318 ci , 302 ci 305 ci and my 6.0 Diesel. Hands down the Diesel! Not just the motor but the transmission. The diesel makes the drive much easier on the driver. You can pull a trailer with anything it question is how long will it last and how will it stop. My f350 have the best stopping power that I have ever felt. Diesel truck cost more to purchase. Diesel trucks cost more to maintenance. Diesel trucks fuel costs more. I still will take my diesel over any gas motor. Diesel trucks can add extra fuel tank in the bed. Some people haul four 5gal. fuel cans in there bed. Look at the trucks in a campground that pull large trailers and talk to the owners. Just pulling in to a truck stop for fuel is worth the price. I do not care to try to fill up in a gas station with the people that are idiots. Your trip will be a pleasure with a diesel. If cost is a problem than purchase the gas motor and just get out there and go camping that is the thing that is most important.

skirk55 said:

Just pulling in to a truck stop for fuel is worth the price. I do not care to try to fill up in a gas station with the people that are idiots.

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I'm glad that this is not the prevalent attitude here.  Just sayin . . .