8V92 vs. S60

[Jerry Winchester]

AG09,

If you are close to Houston you can come see two coaches and both engines for yourself. I just sold my 8V-92 coach and it is stored across the airport from the one with the Series 60. I personally liked the 92, but I had a long history with them, so I wasn't spooked. I'm like Ray; the 60 rattles when it idles, starts easy enough and has a bunch of low end torque. And it gets better fuel mileage and makes a big whistling sound when you go thru the tunnel at Mobile Bay and stick your foot in it.

Jerry

[aggies09]

Jerry,

thanks for the offer. I am in Abilene, so about 7 hrs. drive time from you. I'll keep that in mind as we continue this process. thanks.

[Jon Wehrenberg]

Back on the ground and reading this for the first time. One thing I kept looking for is a price range.

Buying a Prevost is a whole lot more than an 8V92 versus Series 60 issue as just about every owner here will acknowledge.

First, decide how much you are going to spend. If your budget is $150,000 max, you already made the decision to get an 8V92, because any coach with a series 60 at that price is suspect as to its condition unless the owner is dumping it.

If you are budgeting over $250,000 your coach is going to have a series 60 unless someone has a gold plated 8V92 that you just have to have. In between those two numbers you could find an exceptionally well maintained and equipped 8V92, or a less well maintained and equipped series 60. There are exceptions of course but it is the dollars that determines the engine.

I would not hesitate to get either engine, and at this stage, having had both except for the MPG I still like the 8V92 and the ease of access for maintenance or repairs. I am not looking forward to the day I have to disassemble the cabinetry in our coach just to get the valve cover off our engine (series 60) for work on the valves or injectors.

There are far bigger concerns than the engine. Ranking at the top of our list is over the road air and a private toilet. They are significantly more important to my wife and I than the engine type. We also will not go back to a 40 footer because the extra 5 feet have made a huge difference in livability. A 45 footer guarantees a series 60.

Take your time, ask lots of questions, go see as many coaches as your can, and before long you will know you have found the right coach. The hard part is looking past the colors and the little things to focus on the layout and systems that make the coach perfect for you.

[Joe Cannarozzi]

Jon was I off the mark on the HP rating and its influence on operating temps for the 8-V?

[aggies09]

Jon,

Thanks for the input. I have tried to enter this with an open mind and have intenionally tried to not put hard and fast rules in place until I better understand the systems that are most important to liveabiltiy and reliability. Consequently, I haven't established a purchase price budget, other than to say that as a first coach, I would rather be on the lower end of the spectrum than the upper.

I do believe that there are living area issues that are going to be important to us, (private toilet......in such a small space you need some place to be alone for a minute) but I am trying to get up to speed on the mechanical systems so that I can make an informed decision.

Can you give me a crash course on OTR air and why you find that critical?

[Orren Zook]

Joe,

I'm running bigger injectors and 'custom' tune from the DD shop (dyno 480hp) on my V8 and my normal operating termperature is always at 175, unless on a sustained hard pull (like Fancy Gap) when it might run up to 185. I usually tow a Jeep Grand Cherokee and sometimes I tow a 27' enclosed trailer as long as I use some common sense, I don't see a change in temperatures. I seldom run over 65mph - I set the cruise at 1800 and just tool along enjoying the scenery.

[Jon Wehrenberg]

AG09,

There are some polarizing topics about Prevost ownership, and one of the more contentious ones is over the road AC (OTR) versus a converter's version of OTR or the use of roof AC units versus Cruise Airs.

I will state my opinion and reasons. I am correct, and those with differing opinions are wrong. That is all you have to know.

The advantage of OTR is it is a whole bus AC and heating system. It is engine driven and has somewhere in the range of 80,000 BTU of cooling power. No matter the outside temperature you will be able to remain cool and comfortable, and if for some reason your coach is heat soaked, there is little that will match its ability to make your coach comfortable in a hurry.

To put this in perspective, the average roof or Cruise Air has 13,000 BTU, and all 40 foot coaches and almost all 45 footers that I have seen have three units. Some 45's may have four units making the total cooling power (not including the driver's AC or the converter's AC) of approximately half that is available with OTR. The OTR system was designed to cool 45 passengers in the desert southwest. The average passenger is a heater equal to about 500 watts so the system is very capable.

OTR is as simple as it gets. If the engine is running, turn it on and set the temperature. You do not have to worry about starting the generator, or using the inverters to run an AC or two rather than charging the batteries, or how to keep the bedroom cool while you are running the front ACs so you can be cool when you are driving into the sun with that huge solar panel called a windshield.

Here is the stated downside to OTR. It uses about the equivalent of 1/2 bay. It is always located in the 3rd bay back on an XL, and the condenser side and the evaporator side occupy about 20 to 24" in depth. The remaining space is your fuel tanks so while you gain some bay space it is not a lot. Another argument is that the compressor takes a lot of HP.

For those that are mathematically challenged the energy to cool the coach is the same whether you use your inverters to power the AC units, your generator to power the AC, or your engine to drive the OTR compressor. No matter what AC system you end up with your alternator or your generator or your engine will be driving it, and they all use energy.

It is my opinion that we spend a lot of money to buy a high class coach. It is foolhardy to accept less than the best in terms of comfort and convenience. I want to stay cool and comfortable in the worst heat of summer and I do not want to have to compromise. Nothing else out there equals the capability of the Prevost OTR system. But going further, if I was forced to have a coach without OTR I would not accept a coach that required Cruise Airs to provide cooling while driving. The condensing units need a good flow of cool air, and the heated air radiating from a highway in the summer is often so hot the performance of the Cruise Airs is compromised.

So I would thus opt for a roof air equipped coach. While three roof airs may be adequate for a 40 foot coach, I would insist on no less than 4 for a 45 foot coach. A roof air unit is going to get clean, unheated ambient air while going down the road so it will operate efficiently, but they may be a little noisier. The real advantage to the roof air units is they are cheap. When one quits, throw it away and get another at Camping World.

Cruise Airs are pricier but if used solely to cool the coach when parked they are fairly quiet and they are robust. That is what we have now, and the combination of OTR and Cruise Airs to run from generator or shore power works well for us.

There are numerous side issues relating to this decision, and different owners have different needs, so listen to the opposing opinions which are sure to follow this post. Also recognize that some people have different tolerance levels for heat and cold. I like cold. I want a 72 degree coach driving across the desert with outside temps hovering around 105. Others are putting on sweaters when the inside temp falls below 85. You have to put things in the context of how you intend to use the coach, and what you decide is acceptable cooling.

Bear in mind one thing.....one way to sort out what owners value is to see how many that have OTR would give it up, versus how many that do not have OTR that would want it.

Count me as one that has OTR who will not give it up.