ACDNate
First off, one of the most important requirements in obtaining or evaluating a motorhome is the FLOOR PLAN. If it's not to your liking or, the Mrs, is not too happy with it, then it doesn't matter if it's got JET engine in it, Mom's not happy, you won't be either. Now, much of these requirements or, parameters in searching for a coach, tie in with each other. That is, in about 99.999% of the diesel pushers out there, the entry door is in the very front right of the coach. There are some wives, girl friends, even husbands that are not fond of that placement of the entry door.
There are, very, very few diesel pushers that DO HAVE the entry door in the middle of the coach, very rare. Enough about that. One of the most noted and dominant differences in gas vs diesel coaches is the ride. 99.999% of the diesels (especially pushers) ride on air bag suspension. Typically it's a smoother ride based on other given conditions, i.e. tire pressure, tire size, weight of the coach, how it's loaded, how the component equipment i.e. fuel tank. water tank, and more are placed and things like that.
As has been stated, diesels, again especially pushers, will provide a considerably quieter environment while driving. Mainly because the engine is anywhere from 32' to 40' behind you. No wonder you can't hear it. The transmissions in around 99.999% of the diesels are Allison. The ones from around '02-'03 on are the 6 speed versions. They're basically bulletproof.
Diesels have stronger frames, heavier axles, heavier suspensions, heavier tires and wheels, larger and more capable brakes and, they're equipped with one version or the other, exhaust brake or, compression brake. Both of those versions SERIOUSLY help in braking and, seriously reduce the frequency of replacement of service brakes. Almost all of us that have either of these two versions of auxiliary brakes, will get a minimum of around 150K miles or more on our service brakes.
Along with all those mentioned attributes of the diesels is normally higher GVWR and, towing capacity. They have these higher ratings due to the fact that their DIESELS and, diesel engines develope much higher torque, at much lower rpms. The HP ratings of diesels comes into play but, you have to get a fairly large coach to get into the ultra high HP of say, 450 or more.
So, in a diesel, you're going go down the road, with a much quieter ride/environment which provides for basically a much more relaxed drive and trip, not guaranteed but, much more than gas.
And speaking of gas, don't let anyone kid you. Our previous coach was a '99 Fleetwood Bounder 34V with the Triton V-10 275HP. It was equipped with the 4-spd automatic. Did it "SCREAM" going up grades, yep, you bet it did. But that era gas coach had less gears so, there's less choice for the motor to use, while climbing or, just laboring of anytime.
But, step forward several years, and not only I but, many on here have read several times of complaints of how noisy the V-10 is while climbing grades. Many have asked what kind of additional insulation can be placed or glued to the underside of the dog house cover. Now, each coach builder does its own dog house cover insulation so, some V-10s might not be as noisy as others. And, also as has been stated, the newer versions have 6-spds to help with utilizing the Tritons torque and HP range.
But, if you look at the HP range of the V-10, it's up there in the higher rpms so, those engines HAVE TO REV in order to make peak HP. And, when climbing grades, the engines ECM and transmissions and transmission TCMs talk to each other to determine just what gear is needed, at any give speed, while climbing.
So, enough about that. You asked about GM. Well GM pulled out of the race quite a long time ago, leaving basically Ford to reap the bennies of selling to the RV world. Same with Caterpillar, they pulled out a while ago, leaving primarily Cummins to handle the supply of a very, very large percentage of diesel coaches out there. Oh yes, there's a couple of other diesels but, mainly front engine versions like Super Cs, Class Bs and the like.
99.999% of your gas coaches will have lower GVWR and, lower towing capacities. A very large percentage of your diesel coaches will come with a large, around 2,000 watt or more, "Inverter/Charger" that will handle many of the electrical appliances in the coach, without running the gen or, tied into shore power. The gas versions won't have these. The latest diesel coaches (not all) are equipped with residential refrigerators.
There's way more info that can be discussed pertaining to the choice of gas or diesel. The very first and smart thing to do is,
1. Go to an RV show to get side by side comparison of both versions.
2. Take a test drive in as close to comparable length coaches, gas and diesel, as you can, running the same test course, climbing the same hills or grades, cruising the same freeways and, do this as close in timing (another words, try and do the test drives in the same day if possible) as you can so that your memory is as fresh as possible for real time close comparisons.
From there on, there's much personal choice. Cost is always is huge factor too. You can obtain a few year old diesel with some very nice amenities for a pretty good reduced price. Compare this to a newer model gas and to us there's no comparison. We'd choose the diesel every time. Good luck.
Scott
