A great warranty is a great way to avoid costly repair bills.

But with General Motors Corp. and Chrysler LLC on the verge of bankruptcy, will they have the money, or even be around, to fix any problems you might have?

Probably. And even if they can't, the government will.

Because of all the recent turmoil in the auto industry, President Obama has taken the unprecedented step of establishing the Warranty Commitment Program.

It says the federal government will honor the full warranty on any new GM and Chrysler car or truck sold from March 30 until the automakers' financial problems are resolved -- even if that requires a trip through bankruptcy court.

(Here's where to find out all the details about the Warranty Commitment Program.)

It can't resolve all of the potential problems you might have.

If, for example, your brand is eliminated, its dealerships might close and someone else (such as another brand of dealers) might be hired to do the work.

That means you might have to travel further and trust your car to an unfamiliar repair shop.

But the bottom line is clear: If you buy a new vehicle, even from GM or Chrysler, your warranty almost surely will be honored, exactly as you've been promised.

That's good, because GM and Chrysler are among the auto companies offering the most comprehensive warranties we've ever seen.

The guarantees on many 2009 cars and trucks are so good that you could go five years, or longer, without a major expense, no matter what breaks.

There are two basic types to ask about and compare:

• A bumper-to-bumper warranty that covers virtually every part, from the radiator to the trunk latch. Every car has one that protects you for at least three years or 36,000 miles, whichever comes first.
• A powertrain warranty may extend that protection for the major mechanical parts that make the car go, including the engine and transmission.

Before clicking here to see a brand-by-brand rundown of all the warranties on 2009 models, check our choices for the best guarantees in the business:

General Motors starts Chevrolet, Saturn, GMC and Pontiac buyers off with a three-year, 36,000-mile, bumper-to-bumper warranty.

Cadillac, Buick and Hummer buyers have four-year, 50,000-mile. bumper-to-bumper protection (a typical guarantee for pricier, luxury vehicles).

When that expires, a five-year or 100,000-mile powertrain warranty picks up.

That coverage is transferable, which should boost the value of your car or truck if you sell before it runs out. And as long as any part of the warranty is good, you've got free roadside assistance.

That's not a trivial perk. Just call GM's 800 number and it dispatches a service truck that can tow you to the nearest dealer, change a flat, open the doors if you're locked out or provide a splash of gas if you're empty. You won't need to pay for AAA or other roadside programs if you have this.

Hyundai advertises that it has "America's best warranty." Kia isn't as brash but offers almost identical protection.

Buyers are initially covered by the longest bumper-to-bumper warranty you'll find -- five years or 60,000 miles. You can't get that kind of protection on a Mercedes-Benz or Lexus.

The South Korean carmakers follow that with a 10-year, 100,000-mile powertrain warranty that only covers the original purchaser. So if the vehicle is sold, it's over.

Roadside assistance is part of the deal for the first five years or 60,000 miles if it's a Kia, or five years with unlimited mileage if it's a Hyundai. However, Kia offers a five-year, 60K-mile courtesy transportation warranty that Hyundai does not, although you may be eligible for transportation assistance if you are within a 5-mile radius of the dealership.

Mitsubishi now matches the Hyundai warranty, including the five-year, unlimited mileage roadside assistance.

BMW has a four-year, 50,000-mile, bumper-to-bumper warranty with no additional powertrain coverage. Roadside assistance is provided for four years regardless of mileage.

While that is pretty much middle-of-the-road for those parts of the warranty, what makes BMW's warranty better than most is that it covers all factory-recommended maintenance.

Oil change? Covered. Brake pads? Covered. New spark plugs? Covered.

The joy of owning such a precision piece of machinery is often tempered by what it costs to maintain it. Now, BMW buyers can just sit back and allow their dealer to maintain their high-performance rides in impeccable working order without bringing their checkbooks with them.

Chrysler LLC provides Chrysler, Dodge and Jeep buyers with a standard three-year, 36,000-mile, bumper-to-bumper warranty and roadside assistance.

Then the new lifetime powertrain warranty picks up for as long as you own the car or truck. When Chrysler came out with this in 2008, it was the first time any automaker had offered an open-ended guarantee.

Unfortunately, it's not transferable, doesn't include roadside assistance and requires the vehicle to be inspected at a Chrysler dealer within 60 days of every five-year anniversary of the purchase date.

But the inspections are free, and unlike the seven-year, 70,000-mile powertrain warranty it replaces, there's no insurance-like deductible when repairs are needed.

A final word about the extended warranties dealerships and independent insurance companies may offer. With manufacturer warranties this good, you don't need to buy an extended warranty.

Save your money.

By Bill Visnic and Michael Strong

Interest.com Contributing Editors