By: Mike Allen, Saturday Mechanic
Winter is tough on cars and drivers. Take a little time now that the days are longer and do a few simple things to improve your fuel economy and make the grind of commuting (or road tripping) easier on your car and yourself.
1) Shed weight
Go through your car and remove everything you don’t need. That includes stuff like the sandbags you put in the trunk for traction, the ice skates, the air conditioner or tire chains you stored in the trunk for the winter, that box full of stuff that’s been in the trunk so long you can’t remember what’s in it. Ditto for everything in the back seat and under it, that extra gallon of washer fluid and the chainsaw. Leave only the spare tire, jack and lug wrench and maybe the jumper cables. Removing 100 lbs should improve your fuel economy by about 2%.
2) Shed drag
Likewise, remove the ski rack and cartop carrier until you need them. A cartopper can increase fuel consumption by as much as 15% on the freeway—even if there’s nothing in it. A ski rack or roof rack can eat up 5% of your high-speed fuel. You should even remove the crossbars in your factory roof rack, which probably can be done without any tools. Aerodynamic drag is a substantial part of the work you engine has to do at 70 mph-reducing it helps a lot. If your car never hits the freeway, you probably won’t see much difference.
3) Pump up
Actually, you should be doing this every month or so anyway: check the tire pressures. Set them cold, first thing in the morning to the high end of the manufacturer’s spec, which is on a placard in the door frame or in the glovebox, as well as in the owner’s manual. Low tires have more rolling resistance, which eats gas. Being 20% low on the tire pressure can increase fuel consumption as much as 5%. Even late-model (2006 or newer) with tire-pressure-monitoring systems need their tires checked regularly.
4) Breathe right.
Air cleaners in modern cars are amazingly good at separating dirt from the air your engine breathes, and are very long-lasting. But springtime is a good time to inspect the filter and at least knock the dirt out of it. Just toss it on the ground a few times, and bend it back and forth to loosen things up. If you have a vacuum handy, clean the filter element and the inside of the air cleaner box. Follow up with a damp rag inside the air box, and give all the hoses and ducts between the air inlet, air box, and the engine’s throttle assembly a good look-see. A cracked or loose pipe could admit dirty air, shortening your engine’s lifespan substantially. If you drive dusty country roads a lot, you may well need to replace the element annually.
5) Check the computer
A handheld diagnostic device such as CarMD plugs into the OBD port under your dash, and will give you a window into the workings of your engine. Often, a minor problem like an intermittent misfire or a lazy catalytic converter will leave a “pending code” in the computer. The problem may well be a transient caused by a bad tank of gas, a dirty mass air flow sensor that finally responds to its own self-cleaning routine, or some other glitch that doesn’t trigger a full-on trouble code and turn on the CHECK ENGINE light yet. Pending codes will in fact clear themselves if the problem resolves itself, but meanwhile may be costing you in MPG without your even realizing there is a problem. A CarMD report will tell you what codes are present, what they mean and some of the most probable repairs for the problem, which you can address if and when the CHECK ENGINE light comes on.
If you’re not ready to invest in a diagnostic scanner such as a CarMD Vehicle Health System, some auto parts stores have a scan tool you can borrow for a half-hour—but be prepared for highly technical data you may need to have interpreted by a qualified service technician, not the $8/hour counterman who usually sells batteries and fuzzy dice. If you do find a pending code, write down the number, the mileage and the date for further reference; it may be of tremendous help to a service technician at some future date when the CHECK ENGINE light actually comes on.
Mike Allen is a longtime automotive expert and journalist. He owns and publishes SaturdayMechanic.com, a website dedicated to people who still believe in repairing their own cars. Mike spent 25 years at Popular Mechanics magazine, finishing his stint there as Senior Automotive Editor. His Car Clinic column was syndicated by the NY Times, reaching nearly 20 million readers weekly. Mike has appeared on national TV numerous times, including Monster Garage, Mythbusters, NBC Dateline, Paula Zahn and numerous regional shows. He’s also a current ASE-certified Service Technician.