8V71 . . . the Model T of bus engines.

For 25 years it was virtually the only engine available in a motorcoach.

No one complained because it worked. Any klutz could work on one. (Me, for example.)

Then came choice, followed by confusion.

Emission regulations, higher fuel costs and the entry of additional coach manufacturers all acted in concert to bring new engines into the mix.

So, how do you choose which engine is best for your operation today?

There are lots of considerations, but one overshadows all others.

The BEST engine is ALWAYS the one with the best local dealer.

These new puppies are increasingly sophisticated. All are good and none perfect. Irritating little problems become catastrophes when they linger.

A good dealer will fix them in a timely way, tell you the truth about when to expect your bus back, and keep you updated on potential problems before they snuff your coach.

The engine choice, in the largest order of coaches in my career, was decided strictly on the basis of the local dealers superior performance.

Engine dealers were important in the past but will be critical in the future.

As power plants grow more complex, other than scheduled maintenance, youre going to have factory trained people work on your bus. By most accounts, the 2007 engines are doing OK in trucks, better than expected.

Sadly, coaches arent trucks. We cleverly put the engine in the back, which may unleash some mischief. Confined spaces, trapped heat and craftily concealed components may cause parts that work OK in the front of a vehicle to fail in the rear.

Its sorta like putting your pants on backwards. The coach manufacturers engineering installation is as important as the engine itself.

If youre lucky and have several good dealers nearby, then consider the engine builders regional and national networks. Competence matters, but its as important that they be 'bus friendly.' It does matter how skilled they are but if they wont work on your coach in a timely matter then their skills become less important. A 24-hour emergency hot line is a nice touch. But heres a suggestion: you might even try a 'test' call.

Keep in mind that the engine builders leapfrog each other. The one that is doing best to meet the current standards may be bested in the next generation. Superior technology may be less important than consistent effort at support.

Assuming every dealer is perfect, here are two other things to look at:

How expensive are parts and repairs, as well as rebuilt units? Some high mileage operators are seeing measurable differences between brands. Look at regular maintenance costs, like oil change intervals, filters and any specialized fluids that might add cost.

What does the extended warranty cost and what does it cover? Read the warranty because there may be some surprises. After youve read it, buy it. Surprises or not, the new technology is tricky enough that youll want to share the risk with the manufacturer.

Your engine choice also may impact resale. Generally, a used-coach buyer wont pay more for a particular engine but may ignore your coach in favor of another with the engine he prefers. Its best to be in tune with the market.

Just to confuse you, new engine builders are entering the market. Its a part of the vertical integration process, where multinational vehicle manufacturers are moving towards using their own components wherever possible.

European builders have extensive experience meeting stringent emissions standards, so their engines should be good. Time will tell whether theyll be able to get their truck dealers to embrace motorcoaches.

Coach operators tend to have strong feelings about engines, so its unlikely that the new power plants will be forced into the market. Youll be offered choices initially.

The factors in choosing a transmission almost mirror engine considerations, with two exceptions. There seems to be a noticeable difference in the cost of operating a true automatic versus a computer-shifted manual. Reduced maintenance and fuel consumption, as well as improved brake and tire wear, are strengths of the 'manual'.

On the other hand, the 'true' automatic gives a smoother ride, accelerates better, and requires less driver training. Most drivers prefer it, and it thrives in "stop-and-go" environments. Your choice should be influenced by the kind of work your coaches do.

Drive trains will continue to grow more complex reliability will generally improve but when they break youre going to need dealers to fix them.

If you think its complicated now, wait a few years.

In some parts of the world, the coach itself automatically calls the manufacturer when it has a problem.

Other buses sense when a driver is lost and contact the boss.

Best guess is the next-generation bus wont let me in the door.

Dave Millhouser is an account representative for ABC Companies. Contact him at: dmillhouser@abc-companies.com.