4 Slides ,Gas, Under Powered??

[adguy]

Originally Posted by philjp1

I'm looking at upgrading to a gas coach with a V10, it has four slide outs and a salesman told me because of that I would have trouble in the mountains. Anyone out there got one of these could give me some feedback? Thanks

Just came through the mountains with the exact same unit and didn't have any issues at all.

[ak-snopro]

Agree with Mr. Delongs list of key upgrades, to add to the list I’ve installed a Banks Power Pack kit, consists of a complete new performance intake and exhaust system-the V10 loved it!! Lots more power with less rpm. I’m sold!

[NC25T]

I wouldn’t say the salesperson is lying to you, he just needs to do a better job of understanding what you want and expect from a coach! Not everyone expects to travel up a steep grade at or above the speed limit like we can do in a car.

Will it make it up any highway here in the US? Yes

I had a Bounder 38P which is only a 3 slide coach however it’s also almost 40ft, I pulled a wrangler unlimited. I took a trip west and climbed several steep grades…. Made it up every time w/o any issues… or I guess no issues I wasn’t aware of. I wasn’t going to crest those hills at +55 mph which my x in-laws ATTEMPTED to do in their 30ft class c, they were faster but not by a huge margins. I always took my time knowing I could be crawling along at the top…. But I made it…. If I was heavy on the throttle I am sure at times I could of traveled sometimes +10MPH faster….

No reason a quad slide gas coach can’t make it up any hill. Just like a no slide gas coach, the quad slide coach will be going slow up the mountain but it will make it.

[FPengineer]

Originally Posted by FPengineer

A long as you have not driven a diesel up a +6% grade and do not mind slowing down to 35 mpg on steep grades (with the loaded truck traffic), and tolerate the engine sound, I would say a gasser is fine as long as you stay in weight ratings.

Want to differentiate their are two types of diesel brakes with an appreciable performance difference. Not being in the new DO market, I am not aware of which engine brake systems are being provided.

The standard diesel engine brake is a large 1/4 turn butterfly valve beneath your turbocharger in the exhaust stream which is activated by an electrically controlled pneumatic cylinder. It is operated by the transmission ECM when the “engine brake” switch is engaged snd you take your foot off the throttle. The transmission ECM will downshift within the rpm range of your engine (mine maxes around 2,900). Applying throttle disengages the system.

The Tim Taylor grade of a engine brake is trademarked as a Jake brake. It is a much more complex system that changes timing of your engine valves, decelerates like the brakes are applied, and makes a characteristic loud noise some townships do not endorse. It takes a different (more complex) cylinder head, thus they are not economically added onto standard production engines.

Note that the standard diesel engine brake and the throttle body of a gas motor accomplish the same thing. A diesel engine brake chokes off the exhaust stream momentarily turning your engine into a dead headed air compressor. Gas engine wise,
taking you foot off the velocitater (gas pedal) shuts a butterfly in your intake track resulting in a dead headed vacuum pump. Both are similarly effective. (Diesel engines have no throttle butterfly in their intake systems).

When you reach the peak of an upcoming +5% downhill grade, I suggest slowing to 45 at the top of the peak and selecting a lower gear. Do not worry about overspending your engine, the transmission ECM will not allow the unit to drop into that low of a gear. If you gain speed going downhill, the ECM will force an upshift to prevent “redlining” your engine. If you must user brakes, brake moderately hard to burn off day 29 mph, then get off the brakes to allow them cool between brake applications. You do not want to ride your brakes continuously down a hill. That will result in overheating and potentially glazing the surface of your brake pads or shoes. If you smell your brakes, see smoke coming from your wheels, or the surface of your disc rotors are the color of a rainbow, you have cooked them.

With experience on grades you can raise your approach speed as your learn the capabilities of your drive train and how your coach handles.

T Hudson, CDL
1998 Safari Serengeti (40’, 27,000#s)
3126 CAT (300 hp), Allison 3060
acquired 2017

Need to correct a typo. In braking on a long downhill run, I intended to state to burn off 10 mph in brake applications, certainly not 29 mph. I hope I am preaching to the choir on these points. “Happy motoring”.

[NeilV]

Originally Posted by philjp1

I'm looking at upgrading to a gas coach with a V10, it has four slide outs and a salesman told me because of that I would have trouble in the mountains. Anyone out there got one of these could give me some feedback? Thanks

It honestly depends a lot on you as in how you drive, how you load the coach and what your expectations are.

I have been driving a 35.5 foot coach with 2 super slides for over a decade on a 2001 Ford F53 with the V10 towing a small SUV along with having full water tanks and supplies for my wife, 2 adult daughters, 2 large dogs and a cat so it is a coach often loaded to its max stated weight capacity. The F53 if driven correctly can keep up with most of the diesels in most situations within the law. Yes like other heavily loaded trucks you at times have to shift to a lower gear and go up steep grades at less than the MAX posted speed limit and may even have to pull over into the Truck lane however that is not trouble. A newer F53 with the extra HP and improved transmission with more gear ranges should do even better.

To me the real problem with some of the newer coaches more so than extra slides or weight is the increased height of them. With more frontal area, then you need more power to keep those coaches moving at highway speeds. Well over 60% of your fuel can be used at times to push air out of the way at speeds over 40 mph and the taller the coach the more air your pushing down the road. You can more easily adjust your loading to keep the weight down however there is little you can do to change how much air your pushing without physically modifying the front end of your couch.

Be mindful to that 19.5 and 22 inch tires are only speed rated/tested to 70 mph and not for extended periods of time or at extreme temperatures so regardless of Gas or Diesel you still need to be aware of those limits and drive within them otherwise you may be found among those who experience a blowout which is actually trouble.

The V10 is a fairly high rev engine and is built for that however if the dog house is minimally sound insulated you can mitigate that by adding a layer of Dynamat Sound Insulation to the underside of the dog house/engine cover. That was the only real engine modification that I made to my coach aside from changing the air filter inlet to the newer J-Tube design (basically a plastic trap with the inlet higher up behind the hood) better suited to torrential rains sometimes experience during mountain driving. Some may also experience higher noise levels when the engine fan clutch is not working correctly and is stuck in the engaged mode of operation so if you find that its constantly roaring then the fan clutch may be in need of replacement.

The need for a turbo-charger or super-charger for driving gas engines at high elevations was basically rendered moot with the advent of electronic multi-point fuel injection (EFI/EMFI) which the V10 has. Gasoline engines with carburetors back in the day had trouble at higher elevations because they needed to be readjusted manually to deal with the changes in intake manifold vacuum at the higher elevations while diesels since they do not have a throttle plate and do not rely on intake manifold vacuum basically don't have any usable intake manifold vacuum so don't have that problem which is why they require a separate vacuum pump to operate vacuum powered accessories.

In the current day since computer controlled fuel injection was adopted on gas engines the engine control module/computer takes care of automatically compensating for elevation and differences in intake vacuum so that issue is now basically non-existent.

I like my turbo-charged diesel vehicles along with the gas powered turbo-charged ones too however the non-turbo ones with EFI are also just fine for mountain driving. Some based on their wants or perceptions may view the gas non-turbocharged vehicles as troublesome in the mountains however they're really not troublesome but just not meeting an expectation level that perhaps might not be realistic.

If you want troublesome then drive a old carbureted gas vehicle with drum brakes up in the mountains on a cool damp day and experience carburetor icing and total loss of power until it warms up enough to melt the ice in the carburetors venturi and throttle plate or drive too long beyond the speed rating of your tires and have a blowout. Thats trouble and then real trouble.


Take the coach for a test drive and if possible take on the steepest hill in the area and see how it drives. Have them top off the fresh water tank to have it somewhat loaded. If your not trying to break speed records and not driving it like a sports car you will likely find it totally acceptable. Perhaps having limitations but not troublesome.

[Ken Thompson]

I may have missed it somewhere in this post, but has anyone mentioned the loud gas engine beside you, and the additional heat in the motorhome from the engine in the front? I wonder if the people who say they don’t have any problem in the mountains are going up the 6%-8% hills at more than 35 MPH? Not sure how they go down those hills without glowing brakes.

[Norcolmille]

good call out - a friend just traded her v10 front engine for a reasonable diesel pusher - for those and other reasons. Used values can get you a great class A - just need to do maintenance B4 you take that first long trip

[peggwn]

We have what is agruably the best big block gasoline engine ever, the 2000 Chevy Vortec 454ci (7.4L) EFI. Our coach came with the full Banks Power System (incl. Air intake kit). When we first got it new to us it ran just "fine" and could handle steep grades, but with a lot of down shifting that happened sooner than I would have liked. We did add sound deadening material to dog house, so even in lower gears the sound level is tolerable; while cruising the sound level was fairly low and we didn't really have to raise our voices. We cruised all day at 65 MPH, 2200 RPM. We recently swapped out our original ECM for an UltraPower ECM. We now have more pickup/pep, less shifting on inclines, and somewhat quieter running at a slightly lower RPM when cruising at 65 MPH. I also suspect because of that we also may have some MPG improvement.

Our Itasca Sun Cruiser 32V has one large slideout and the GVWR is 18,000 lbs. We don't really need a diesel engine because we have a light-ish coach, we don't tow often, and we only do a few hundred miles per trip. We love the floor plan and interior. So, the bottom line as several others on before have said - determine your budget, pick something you and yours like, figure out what kind of use you plan to make of it, and then go for it. Of course you should thoroughly check it out before any money changes hands and you drive it off. Good luck, have fun, and travel safely.

[yeloduster]

Originally Posted by Ken Thompson

Not sure how they go down those hills without glowing brakes.

Refer to post #33 in this thread. A gasoline engine is an ENGINE BREAK. Driven properly a heavy vehicle with a gasoline engine can descend a grade safely at a reasonable speed.

Diesel engines on the other hand are not engine brakes and need a device added to the engine or exhaust to provide engine braking.

You just have to know how to drive it. It ain't even that hard and it ain't a mystery. When you close the throttle on a gasoline engine you shut off the air to the engine. The resulting vacuum is a powerful force against the engine turning. This is a natural phenomenon of a gasoline engine.

Since about 2006 heavy vehicles with gas engines have smart technology that uses a computer to control transmission shifts. The computer cannot anticipate what is coming next so is not perfect. The driver has the responsibility to assure that nothing gets out of hand. Of course, if the driver were driving a vehicle with a diesel engine he would have the same responsibility.

[Iceman-31D]

Originally Posted by Old Harry

I’m not going to go into “will a gasser make it up the hill?” discussion, short answer is yes. The thing no one has addressed is the engine noise from a gasser vs. diesel pusher. My wife and I, two months ago, traded in our 2012 Tiffin Open Road for a 2014 Tiffin Breeze. Not because the Open Road couldn’t go up hills, it could, and would keep going at highway speed. We got a DP because even going up a small but long hill or even some highway overpasses the V10 would start down shifting and by the time it got to the top of the hill it would be at 5,000 rpm and screaming in our ears. I’m talking about “hills” not mountains. My cruising speed is between 60-65 MPH so I wasn’t trying to keep up with car traffic.

My wife and I are retired, don’t full time and we tow a Toyota Prius on a dolly and carry about a half tank of water so we were not overloaded. On the last trip from Florida to Honea Path South Carolina both my better half and I felt we were deaf from the engine noise. We are planning a trip to California in 2022 to see some of her family and we agreed we were not making that trip in the Open Road or any other gasser.

Just something to think about.

I have a 38' gasser (v10) that is 24K loaded, and I tow a car. The revving described above can be avoided. I installed the "5-Star tuner" in my rig, and now I climb the hills he describes at 3200 RPM and carry on normal conversations. I have little to no downshifting on normal hills, and an overall pleasant experience. The noise level is highly rig-dependent (and maybe build quality that day?). I had a Thor class A with a V10 and the engine noise was horrendous; then got a 34' Tiffin V10, and the engine noise was much reduced. Now I have a WBGO and it is the quietest of all 3 by far. Long story short, a 4-slide rig with a V10 is no problem in the mountains or otherwise; Just cheaper to buy, run, and fix than a DP.

[BOSTONBERNIE]

Traveled many miles through the mountains with a v-10 towing a jeep wrangler unlimited,with no problems whatsoever,but only after installing a5 star chip, go to there site and see if its for you, was very pleased when i owned my 33 c gasser.

[NeilV]

Originally Posted by Ken Thompson

I may have missed it somewhere in this post, but has anyone mentioned the loud gas engine beside you, and the additional heat in the motorhome from the engine in the front? I wonder if the people who say they don’t have any problem in the mountains are going up the 6%-8% hills at more than 35 MPH? Not sure how they go down those hills without glowing brakes.

Yes others have mentioned engine noise as an issue with the V10.

I drive in the mountains regularly and having to use the truck lane on steep grades is not trouble. No glowing brakes if you drive down grades responsibly so if you do have that problem, its most often unfortunately a problem with the driver which I understand many won't want to hear however it is what it is. Engine braking does work quite well in gas engines and will save a lot of brake wear. Driven responsibly and reasonably glowing brakes are not a problem in gas vehicles even when descending long grades. If you have such a problem then its time to review your driving technique and make some much needed corrections to how you drive.

Most perceived problems people have driving in the mountains is an educational issue and not a fault with the vehicle except in the cases where maintenance has been lacking, again which I understand many don't want to hear.

[KKTravel]

I am not currently a motorhome owner - but tow a travel trailer with a 2012 Ford pickup. The gas rigs from that vintage had "tow/haul" mode that electronically controls the transmission and I use it all the time in the mountains. It works very well - altering shift points for ascending power and especially on descents will hold in a lower gear giving you engine braking to control speed. I would think a newer motorhome would have that same feature, or as mentioned you could get a chip or programmer to add this.

[Johnynorthla]

All of these reply’s are great info. However, the BIG question here is CCC. These rigs have been in production for a very long time. All of them will get you where you need to go, all at a reasonable speed, some noisier then others, etc.. listing GVWR is important but, if you can’t put more than 2 humans and only a few items stored inside them because of weight restrictions that could cause anything from a blowout to a fatal incident, what does it matter how well or loud it goes up or down a grade, if safety is compromised?!