Tired Of Poor Mileage
Make sure your tires are properly inflated. Under-inflated tires cause more resistance to travel, and they force the engine to work harder. Let the tires cool down before checking their pressure. Car manufacturers are required to place a label in the car stating the correct tire pressure. This label may be found on the edge of the door or door jamb, in the glovebox, or on the inside of the gas cap compartment cover, depending on the year of your Corvette. If the label lists a PSI range, use the higher number in order to maximize fuel efficiency.
It's important to note that radial tires can be under inflated yet still look normal, so check the tires with a gauge-digital gauges are the most accurate. On average, tires lose about one psi per month and one psi for every 10-degree drop in temperature. I was curious as to why tires lose pressure for, what on the surface, would seem to be no reason at all. For the answer, I contacted Mark Cherveny, the tire product specialist at Goodyear.
Mark says, "Like a balloon, tires hold air pressure. for a tire, it is within the cavity between the tire and the wheel. However, changes in ambient temperature cause the tire pressure to fluctuate (this is why tire pressure should always be checked when the tires are cool, preferably in the morning before driving the car more than a few miles).
"Also like a balloon, the pressure difference between the inside of the tire and the outside of the tire creates a pressure gradient causing some small amount of air permeation to occur due to the size of the rubber compound molecules and the size of the air molecules inside the tire. A balloon loses a small amount of air pressure over time due to the microscopic nature of the rubber molecules and so does a tire.
"The special rubber compounds we use for the liner of the tire slows the air permeation, but it does not eliminate it. That is why tires need their air pressure checked at a frequency of about once per month or before a long trip."
So how much does tire pressure effect mileage? A lot: under-inflated tires cause fuel consumption to increase by as much as 6 percent, cause the tires to wear quicker, and can make it difficult to handle the vehicle. And, while we're on the subject of rolling gear, be sure your wheels are aligned and your brakes are properly adjusted to minimize rolling resistance. Out-of-line wheels, as evidenced by uneven tread wear, should always be aligned by a professional.
Based on this information, monitoring your tire pressure is important, and there are several devices available for doing this. If you own a C5 or a C6, you've got it knocked already since your Corvette is already equipped with tire-pressure monitors, and the exact pressure of all four tires can be read on your DIC.
If you have an older Corvette, you can use tire valve caps that will indicate safe or low pressure at a glance; these are very inexpensive, available from a number of sources, and well worth the money. If you just want to get some additional insurance against tire-valve leakage, then you may want to purchase a set of NoLoss tire valve caps for under $13.
You can also install a wireless tire-pressure monitoring system in your older Corvette to endow it with the same high-tech tire-pressure monitoring enjoyed by C5 and C6 owners. The system comes with four tire-valve transmitters that are installed in each of the Corvette's wheels, and an LCD monitor screen that can be mounted noninvasively on the dash or console. The monitor screen is powered via a cigarette lighter plug (or you can hard-wire it, if you wish), and it provides a readout of the pressure in all four tires with the push of a button.
If you do a lot of autocrossing, chances are you frequently drain or add air to your Corvette tires for better performance on various courses. To add air, you probably bring a portable air tank with you, or, if you really want to be on top of your game, you have a 12V-powered compressor like the one available from Extreme Outback. This small compressor comes with cables to hook it up to your battery, a tire gauge, a flashlight, and it all fits compactly into the nice powdercoated steel case that tucks away in the trunk of your Vette. Even if you don't want to take it along with you, it's an excellent small compressor for garage use, and, since it uses 12V DC power, you don't even need an electric outlet to use it.
So as you can see, none of these tips and suggestions is rocket science, just good old common sense. But they can add up to a significant increase in the mileage you'll get if you put them into practice. Now let's take a look at some of the gizmos you can employ to increase your mileage.