Q: My 1998 Mercury Tracer with 35,000 miles goes through three-quarters of a tank of gasoline during trips of up to 35 miles. I've regularly maintained the car and have changed its PCV valve, spark plugs and air filter, among other things, but to no avail. --S.P., Chicago

A: Your car's small 110-horsepower four-cylinder engine was rated at an EPA-estimated 28 mpg in the city and 37 on highways, but your letter indicates it's delivering worse fuel economy than a mega-horsepower exotic sports car. The only thing that really makes sense here, assuming there's no fuel leaks, is that a malfunctioning fuel gauge is causing your distress. Elmwood Park's Caira Automotive says it has encountered "troublesome fuel gauges" in the 1998 Tracer. It suggests that you see how many gallons it takes to fill the tank when the gauge is at the one-quarter mark.

Q: Will the stylish new Chevrolet Malibu get a high-performance SS model? --F.S., Hammond, Ind.

A: I wouldn't bet against seeing such a model. For now, though, the LTZ with its 252-horsepower V-6 and fairly wide (50-series) tires on 18-inch wheels is the hottest Malibu.

Q: Will we ever see a diesel-electric hybrid car? --J.M., Chicago area

A: That's very likely because such a hybrid would be more fuel-thrifty than a gasoline-electric car. Modern diesel engines have none of the drawbacks of the old ones, and new low-sulfur diesel fuel is "cleaner" than the old diesel fuel.

Q: What's the strangest print auto advertisement you've seen? --F.S., Chicago

A: A collection of muscle car print ads in the "Muscle Car Mania" book shows a truly bizarre ad for the now-classic Shelby GT Mustang from Motor Trend magazine's August 1967 issue. The ad pictures the Mustang speeding from the front of a house, while a small boy in a cowboy outfit is shown running into the car's path because it was hidden from him by a tree. A woman in the house frantically looks through an open doorway at the scene.

Q: I'm regularly paying more than $3 per gallon of gasoline for my average mid-size sedan. I never paid much attention to fuel-saving tips when gas was cheaper, but I could use some now. --E.W., Chicago

A: AutoZone, a retailer/distributor of auto replacement parts, has these tips: Replacing faulty oxygen sensors can save $429 a year if gas is $3 per gallon. Replacing dirty air filters can save $136 a year at that fuel price. Replacing "forgotten filters" such as the fuel filter, PCV valve and breather filter can improve fuel economy by 15 percent if changed every 12,000 miles. A faulty gas cap seal can waste $50 a year because of evaporation. Also, keep tires properly inflated, avoid excessive engine idling and aggressive driving. Combine errands into one trip. Cruise at no more than 60-65 mph on highways. Avoid carrying heavy items -- generally, the heavier the car, the lower the fuel economy.

Q: I owned a magnificent 1958 Chrysler 300D, and read your article about the high-performance 1957 Chrysler 300C and 300D in the Dec. 3 AutoTimes. But you didn't mention that the 1957 or 1958 300 had a French four-speed manual transmission made by Panta Mussan (a word I've probably misspelled). --J.P., Chicago area

A: I actually wrote that most ordered the 1957 300C with an automatic transmission, but that it "could be ordered with a three-speed manual transmission." That was a standard Chrysler three-speed manual. You're thinking of the French Pont-a-Mousson four-speed manual transmission, offered for the 1960 Chrysler 300F. It was the first four-speed manual put in a post-World War II Chrysler. That manual -- also used in the posh, Chrysler-powered French Facel Vega -- was in no more than 15 300F models because it shifted terribly. Chrysler's three-speed manual replaced it in the 1961 Chrysler 300G. Nearly all 1955-65 Chrysler 300s "letter series" models had automatic transmissions.

Q: Since last summer, my 2001 Dodge Caravan has kind of an exhaust smell each time I turn on the air conditioning/defroster control. This happens if the engine is hot or cold, and especially after starting it. I checked the exhaust pipes, but they seem OK. Mechanics at a shop said nothing seemed wrong. --J.P., Schaumburg

A: The "kind of exhaust" smell probably is coming from under the hood -- if that's the type of smell it is. (Some car owners mistake different types of unwanted auto smells.) If it's an exhaust smell, it is nothing to fool with. Take the Dodge to another repair facility, start the engine and have its technicians determine exactly what type of smell it is -- and then find out where it's coming from and eliminate it.

Car question? Send it to Dan Jedlicka, Chicago Sun-Times, 350 N. Orleans, Chicago 60654, or e-mail djedlicka@suntimes.com. Include name and hometown.