Diesel Puller vs: Diesel Pusher

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gary41

Member
Joined
Dec 12, 2005
Posts
7
Location
Huntsville, AL
We are considering going to diesel power, and have come across a couple of 1998/1999 Newmar Mountain Aire 3758 FL's that are powered by a 5.9L Cummins UPFRONT...has anyone had any experience with these or similar units?? I don't think this type of chassis/engine is being marketed any more.? ?Just wondering the pro's and con's.? Any input would be appreciated.? :-\
 
One major consideration when deciding on a front mounted Diesel is NOISE.  You might consider getting an intercom to hold a discussion with the passenger with a front diesel where as  a diesel pusher is very quiet.
 
Gary,

>> I don't think this type of chassis/engine is being marketed any more.<<

I just got my Christmas CD from Freightliner pushing their new chassis, FRED, short for FRont Engine Diesel, so they are back!? VBG
 
The only significant drawback to a gas chassis is the engine noise up front. With a diesel puller, I would think it would be much worse.  I owned a big diesel pick-up when we had a fifth wheel and noise in that wasn't bad at highway speeds, but that engine is out front rather than right under your feet.

I would want to test drive it extensively on roads that are othewise quiet - little traffic and smooth road surface. See how much noise there is in the cabin.  Play the stereo and have a conversation. Even then its hard to judge what it would be like for 3-4 hours of driving.
 
RV Roamer said:
The only significant drawback to a gas chassis is the engine noise up front. With a diesel puller, I would think it would be much worse.? I owned a big diesel pick-up when we had a fifth wheel and noise in that wasn't bad at highway speeds, but that engine is out front rather than right under your feet.

I would want to test drive it extensively on roads that are othewise quiet - little traffic and smooth road surface. See how much noise there is in the cabin.? Play the stereo and have a conversation. Even then its hard to judge what it would be like for 3-4 hours of driving.

The new Cummins diesels are much more quiter than in past (~80%) and seven decibels less at idle and FCCC is saying that the noise will be equal to ort less than today's gas models. We'll see what public thinks.
 
I was at Gaffney Freightliner last week and saw the FRED. Did not get a chance to drive one but those there that did said it was comprable to a gas coach for noise.
 
Our motorhome would be a "FRED", that's a new one on me. Noise wise I don't consider it too bad. The loudest part is when the fan clucth kicks in, have never ridden in a pusher so can't compare. The engine is a 190HP 5.9L Cummins with the P7100 injection pump, compareable to my '98 Dodge/Cummins that is 180HP with the same "P" pump. However the motorhome has much less Diesel rattle, most likely due to timing differences.

What is the price difference between a pusher and puller?
I can see where a pusher would have more open space under the floor for storage and water tanks.
I managed to get into our coach for under $18k. That was the advantage of an older unit that needed a little work ;D.
 
dsl4us said:
Our motorhome would be a "FRED", that's a new one on me. Noise wise I don't consider it too bad. The loudest part is when the fan clucth kicks in, have never ridden in a pusher so can't compare. The engine is a 190HP 5.9L Cummins with the P7100 injection pump, compareable to my '98 Dodge/Cummins that is 180HP with the same "P" pump. However the motorhome has much less Diesel rattle, most likely due to timing differences.

What is the price difference between a pusher and puller?
I can see where a pusher would have more open space under the floor for storage and water tanks.
I managed to get into our coach for under $18k. That was the advantage of an older unit that needed a little work ;D.


The noise will be much less than yours. Check out a Dodge RAM pickup truck made today with a Cummins siting next to one made over a year ago. Your likely to question whether it even has a diesel in it. The one new motorhome using the FRED that I've seen is the Allegro Bay version of the gas. It has GVW's up to 26,000 and GCVW up to 30,000 - lengths up to 38 ft. The gas sells for ~$117,000 MRSP; diesel will probably be in neighborhood of $120,000 or so.  May be able to buy for ~ $ 90,000 on street.  ???
 
I don't think there is any inherent price difference between pusher and puller.  However, a puller chassis is often also an entry level chassis and there may be other cost saving factors that create a price differential but also contribute to more noise, harsher ride, etc.  Some previous puller models have had 4 or 5 speed trannys, leaf springs instead of air bags, hydraulic brakes instead of air, etc. 

With a pusher you lose substantial rear storage space, inside and out, but gain space back with the cavernous "pass through" mid storage made possible by the lack of a driveshaft running down the center.  With a pusher the engine room encroaches on the rear bedroom, typically costing under-bed storage and/or makng a raised platform in the rear. With a puller, the engine room is under the driving area and typically creates a raised area there, often called a doghouse if it is a center "hump" but in todays pullers the raised front is likely to be pretty much flat.  All this is generalities - individual models will vary widely but there are always tradeoffs.

Fan noise is a biggie in a puller  (gas or diesel) - you really hear the cooling fans cut in when hill climbing or at 95+ temperatures. You are also aware of downshifts. Tire noise should be about the same in both, but air suspensions seem to transmit less noise than springs.
 
The noise will be much less than yours. Check out a Dodge RAM pickup truck made today with a Cummins siting next to one made over a year ago. Your likely to question whether it even has a diesel in it.

On the new HPCR injected engines they are very quiet. However the years he stated, '98/99, those are right in the noisy era of the truck versions. Those could be powered by a 12 valve motor with a P7100 injection pump or a VP44 electronic pump with a 24 valve ISB. Alot of the 24V truck motors are louder than the 12Vs. But being in a med duty chassis they get to use different fuel mapping and timing so they may not be as loud, which seems to be my case.

Dan
 
? Some previous puller models have had 4 or 5 speed trannys, leaf springs instead of air bags, hydraulic brakes instead of air, etc.?

You hit the nail on the head with our coach.
4 speed allison, mono beam front axle with leafs and hydraulic brakes.
Definetly entry level for a Diesel but sure beats a class C or a P30 chassis. I figure general maintenance should see this chassis going 300K, I know the powertrains are built for it.

Dan
 
Having a gas rig, I can agree with Gary's assessment of the tranny shift noise, and you know when the fan kicks in even tho' it's got a variable speed hydraulic clutch. Electric fans can be even worse due to their relatively smaller size and higher speed operation; they're either on or off.

The doghouse doesn't bother me all that much because I drive for several hours at a time and don't have to swing around or climb over it too often. The occasional inconvenience and added noise is relieved to a large extent by the additional under-bed storage and the fact that I spend much more time parked than driving. Besides, having recently installed a much freer-flowing exhaust system, I don't even hear the fan, tranny, or engine anymore. Really have to get that resonator installed again! ;D ;D ;D 
 
Karl said:
Having a gas rig, I can agree with Gary's assessment of the tranny shift noise, and you know when the fan kicks in even tho' it's got a variable speed hydraulic clutch. Electric fans can be even worse due to their relatively smaller size and higher speed operation; they're either on or off.

Karl

I find that our hydraulic fan, located just behind the driver's side rear wheels, is noisier than the "jake" brake on our coach. I can hear it whenever it kicks on, even tho it is about 35' away. However, with a front engine vechicle, the fan should come on less since it is in the air flow as opposed to a side mounted diesel engine radiator which needs the fan to get cooling air over it.
 
Karl said:
I wouldn't have thought youd be able to hear it at all. You're right about the front air flow. The fan mostly just idles unless it's quite warm or you're really hauling up a long, steep grade.

It is a very large radiator and a very large fan  ;D
 
This is an old thread, but I searched for any input on diesel pullers, because we bought one at an RV show yesterday.  It's being ordered from the factory.  It's a 2007 Gulfstream Sun Voyager, and has a 300 HP Cummins Freightliner engine in it. 

The diesel pullers were more expensive with the same or less options, at least the ones we looked at.  The entry level Gulfstream diesel puller was the Crescendo, and they were $116,000.  The one we eventually ordered had a fantastic, three-zone floor plan, so was more money.  We were told by the factory rep that the engine runs very quietly, that the diesel engines that have come out in the past few years are not at all like the ones we've had in trucks.  Gulfstream has been making thiis puller for about a year and they've had very good results so far.  While we realize we're taking a chance somewhat by trying a newer product, we wanted to upgrade from our gas MH and this was the only realistic alternative financially. 

If anyone has had any experience with this make/model, or any Gulfstream puller, I'd appreciate hearing from you. 
 
Congratulations on the new purchase. I haven't seen any of the new diesel pullers up close, so I'll need to get to an RV show sometime soon.

Please be sure to let us know if it lives up to expectations.
 
I sure will.  However, it looks like it's going to be 8-10 weeks before delivery, unless they can find one in stock with the options we've ordered.  So it may be awhile before you hear back from me about the rig! 
 
Not sure where I read it but the review on the front diesel  was not as friendly as it should have been.  But then that may have something to do with Gulfstream entry units themselves.  Good luck.
 
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