Nuts and Bolts with Buffalo Jim

Dear Buffalo Jim,

My husband Pete and I have a bet that I think you can help us settle. We own a 1998 Ford Windstar van, and he says that it's better to fill the tank with premium gas than with regular. He says I'm cheap. I say he is a silly little man. Which one of us is right?

--Kate Mascovic

You know what I think? I think you know you're right, and you're just using my column as a public forum to humiliate your husband. If that's the case, then congratulations, you are indeed correct. Actually, according to AAA, fewer than 10 percent of the cars on the road today need premium gas. The rest will run absolutely fine on the cheap stuff.

The gas-grading process is complicated, but let's just say the octane rating indicates how sensitive the fuel is to heat and compression--the higher the octane, the more it can be compressed before it spontaneously ignites. This is great if you have an old muscle car with a high-compression engine, which will cause low-octane gas to pre-ignite and make the engine knock, but it is unnecessary for a commuter car like your Windstar. In fact, your van has been optimized to run on regular gas, so filling it up with premium may cause a net loss in efficiency.

If you don't believe me, check your manual or run your own street test. Fill up with regular, find a hill and floor the accelerator. As long as the engine doesn't ping or rattle, you've made the grade. If your husband still wants to blow his money on an overpriced liquid, tell him to buy you a fancy bottle of wine.

Clarification

Last week, I answered a question about a van that wasn't getting enough power under load. To review:

"I own a 1994 GMC conversion van with a 350 fuel-injected engine that currently has 180,000 miles on it. Six months ago, I had a complete tune-up done. The van is having trouble once it is warmed up accelerating up slight inclines. It appears to cruise fine once it reaches above 45 mph."

At the time, I suggested the van might have a dirty fuel filter, a bad fuel pump or a partially plugged exhaust. I stand by the diagnosis, but my friend Charlie Robertson at the Nevada Automotive Institute pointed out that the van might also have a clogged fuel injection system--a problem he says is common to those vehicles. It's a point well taken because the average gas tank is basically like a cesspool. Imagine all the crud that gets lodged in there over the life of the car--dirt, leaves, oil, sand, gravel, dust, you name it. Over time, this stuff can build up in the fuel rail, which supplies the fuel injectors, or the injectors themselves. It used to be nearly impossible to completely clean out clogged injectors, but now high-tech shops rely on a high-pressure fuel injection center that connects into the fuel line and flushes out the whole system.

As a final note, never fill up your car at a gas station when it's being refueled by a tanker truck. The high-pressure transfer hoses on those trucks blow the gas into the station's underground storage tanks with such force that it stirs up all the crap that has settled on the bottom over the years. All of this particulate matter then goes directly through the pump into your gas tank. Your fuel filter will catch the stuff 99 percent of the time, but better to just drive on by and fill up on the next corner.

Buffalo Jim is the owner of Allstate Auto Marine. According to a feature in last week's Review-Journal, he is also a budding photojournalist. He is available for weddings and bar mitzvahs as long as cocktail wieners and pizza puffs are served at the reception. E-mail him your car questions and/or celebration dates at buffalojim@lasvegasmercury.com.