If your Corvette is equipped with an overdrive transmission, use it. With overdrive gears, it's possible to still drive at highway speeds, but the engine speed decreases. Overdrive gears reduce both fuel consumption and engine wear. Also, if you have cruise control, use it on highway trips to help maintain a constant, steady speed rather than a variable speed. Maintaining a steady speed helps to reduce fuel consumption. One caveat to using cruise control applies when you're traveling through hilly terrain. Avoid trying to increase speed while climbing a hill, since your engine is already working hard trying to overcome gravity. If you have the cruise control engaged when ascending a hill, the car will try to compensate for the increased gravity and use more fuel, so disengage the cruise control when climbing hills.
Anticipating traffic conditions ahead and not tailgating can improve gas mileage by 5-10 percent. This driving strategy is not only safer, but it will also reduce wear on tires and brakes. When driving in the city, nearly 50 percent of the energy needed to power a vehicle is for acceleration, and unnecessary braking wastes that energy. Also, accelerating quickly causes the engine to enter a less efficient "fuel enrichment mode," whereby additional fuel is delivered to increase the rate of acceleration; in most instances this is overkill, since a lot more fuel than required is actually delivered. Avoid stop-and-go traffic by taking alternative routes or less congested travel times. Consolidate your daily trips and errands.
Avoid unnecessary idling; idling gets 0 mpg. Later-model Corvettes (C3 and newer) do not need to be warmed up. In fact, no matter how efficient your car is, unnecessary idling wastes fuel, costs money, and pollutes the air. If waiting for more than a few minutes in a drive-through lane (e.g., at the local burger joint), turn off the engine. Also, do not leave the car idling while running into a store for a quick errand. This is especially hard on a Vette during the hot summer months and is an open invitation for auto theft.
Be a sensible patriot. Everyone loves the flag, but show your patriotism by affixing a decal rather than hoisting a large flapping U.S. flag or attaching one to your radio antenna, which increases wind resistance. And while we're on the subject of wind resistance, keep your windows closed when possible. your mileage should improve if you keep the windows closed at highway speeds, since air drag is reduced. This is true even with the air conditioning on, assuming the system is in good working order. If possible, try to avoid using your air conditioner in heavy, stop-and-go traffic such as traffic jams or holiday weekend back-ups. Remove any external accessories, such as a luggage rack, surfboard carrier, or other items that lower the aerodynamics of your vehicle.
Get rid of excess weight by removing unnecessary items from the vehicle. You should store only essentials in the trunk, since less weight means better mileage. After a vacation or a trip, make sure you remove all unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your mpg by up to 2 percent. The weight reduction can be realized by eliminating socket sets, jumper boxes, or other such tools you probably won't use anyway if your Corvette is in good running order. This brings us to the next point.
Keep your engine operating at its peak efficiency. A well-maintained engine will help you maximize gas mileage. Incorrect fuel ratio, bad spark plugs, and incorrect spark timing can have a big effect on gas mileage. Follow the service schedules listed in your owner's manual. Replace filters and fluids as recommended; have engine performance problems (rough idling, poor acceleration, and so on) corrected at a repair facility unless you're qualified and have the requisite equipment to do the job right yourself. Studies have shown that, depending on a car's condition, a poorly-tuned engine can increase fuel consumption by as much as 10-20 percent.
Slip Sliding Away
Always use a good engine oil, preferably a synthetic with a friction-reducing additive. These have been known to improve fuel economy by as much as 12 percent. I'm personally a big fan of Royal Purple for my C5, and in independent dyno tests I conducted, I established beyond any doubt this oil increased my horsepower and mileage by a measurable degree. Well-lubricated engines don't have to work as hard, so they produce more power while using less fuel. And don't forget the importance of a clean oil filter, too (I like K&N filters, but that, again is personal preference). The oil filter removes harmful dirt and grit from the engine; clean engines run smoother and easier. The car's air filter keeps impurities in the air from damaging internal engine components. Not only will replacing a dirty air filter improve fuel economy, it will protect the engine. Clogged filters can cause up to a 10-percent increase in fuel consumption due to air-starvation.