At Tuffy Farmington Hills we hear from a lot of people who are excited about the new diesel engines that will soon be available in passenger cars and SUV's. But our Michigan friends are often curious about the preventive maintenance requirements. People may not know that diesel engines have long been used extensively in Europe and Asia. In fact, in some markets, there're nearly as many diesel powered passenger cars as there are gasoline.

Here's who's announced or is expected to announce new diesels for North America: BMW, Mercedes, Audi, Volkswagen, Nissan, Honda, Toyota, Hyundai and Subaru. Of course, the US auto makers will be expanding their diesel offerings as well. Diesels will become a very big deal here in Michigan .

You may ask, why has it taken so long getting to Michigan and North America? There are a bunch of reasons like fuel tax policies and such, but the biggest hurtle was that Michigan diesel fuel had a high sulfur content – too high for the latest generation of highly refined diesel engines. Recent government mandates to remove sulfur now opens up Michigan to the engines the rest of the world's been enjoying for a long time.

Why are diesels so popular worldwide? Well, for starters, diesels get up to 30% better fuel economy than gas engines. And they last a lot longer. And modern diesel engines are refined, quiet and powerful – and there's none of that black smoke we used to see.

Some people may think that diesels create more pollution. But, you need to rethink diesels. Environmental pollution standards for diesel cars and light trucks are scheduled to be as strict as they are for gasoline vehicles. A modern diesel engine is as clean as a gas engine.

You may also have heard a lot in the news about bio-diesel. The exciting thing about diesels is that they're not limited to fossil fuels. They can run on fuel made from vegetable oil. There are refineries that make diesel fuel from cellulosic waste like woodchips from lumber mills. There's even this cool new process where a special strain of algae is used to convert carbon dioxide, water and sunshine into bio-diesel. That's still a ways off, but you can see that diesel can become a sustainable source of fuel.

And, there are not a lot of trade off's with diesel in terms of performance. A modern passenger car diesel is very smooth, quiet and quick. Most folks wouldn't notice any difference. For those who tow trailers and haul heavy loads, diesels will be an improvement.

Now diesel engines are heavy duty, so they cost more than gas engines. But they get better fuel economy – so the break-even point is largely dependent on the difference between Michigan gas and diesel prices at the pump and how many miles you drive. And diesels have a higher resale value.

Now, let's get back to diesel maintenance. You have to keep in mind that most of the new diesels are just coming in, or will be over the next couple of years, so we don't have the maintenance schedules to make direct comparisons yet.

But going off what we already have in Michigan , we can expect fluid drain intervals to be similar to gasoline engines. Diesels do require very clean fuel, air and oil, so their filters are much higher capacity than gasoline filters and cost more. The engine air filter needs to be changed more frequently as well.

Repair costs are similar. As with gasoline engines, proper maintenance is the key to long engine life and to avoiding repairs. So pretty much what we have come to expect with gas vehicles; coolant system service, transmission service, power brakes, power steering, differential, filters, fuel system, and so on. And the payoff for you, if you're the kind that likes to keep your vehicles for a long time, is that a properly maintained diesel engine can last for hundreds of thousands of miles.