Gas Saving Myths
As with any hot topic there are tons of myths about gas and your car’s mileage. Let’s take a look at a few of the more common myths circulating today.
Myth #1: Buy gas in the morning when the gas is cooler, thus denser.
Gasoline is stored in underground tanks, which remain at a fairly constant temperature. I have personally reviewed the tank readings at my local gas station to confirm this fact. It’s like a cave, which stays at a constant temperature all year long due to it’s distance from the surface of the earth. The only factor that comes into play, is when the gasoline is delivered to the tank. When gasoline is transported in trucks, it will expand with heat. If you buy your gas right after the tank is filled, you will receive warmer gas, but I would not stake out your local gas station to find out when the gas truck delivers.
Myth #2: Driving with the windows down at highway speeds without A/C is better than windows up with the A/C on.
When at highway speeds, keep your windows up. On most vehicles, having the windows open at highway speeds will create extra drag and cost you gas. If it’s a hot day, running the A/C is a necessary evil, and will cost you gas mileage, but the loss is about equal to keeping the windows down on most cars. When driving under 45mph, keeping the windows open and A/C off will be more economical because drag from having the windows is not in effect at the lower speeds.
Myth #3: Keep your engine running if you are making a quick stop at the store, it takes more gas to start your engine than to leave it running for a few minutes.
This myth is not true, starting an engine takes very little extra fuel, and it is always better to turn the engine off.
Like anything in life, cheaper is not always better. When it comes to buying gas there are a few things to remember.
Name brand gasonline generally has more detergents, which help your engine run cleaner and more efficiently. I personally use Texaco due to some personal experiences and the fact that I used to work at a Texaco station in high school and college. At the time, the regular gasoline did not have the same additives as the plus and supreme grade. I switched from regular to plus grade, and got better gas mileage. I was driving a 1979 Mustang at the time with a 4 cyl. engine and went from 18 to 20 mpg just by switching grades of gas.
To find the lowest prices, there are websites online, which post almost real-time gas prices across the country. I would also shop at gas stations, which have competition, which will drive prices down. So the more gas stations in the area, the better the price.
When you are at the gas pump, start the pump and then take a walk around your vehicle. You should check all 4 tires for any signs of low air pressure. In all but the higher performance tires, you can see the sidewall of the tire bulge when air pressure drops. Once per month I would check the tires with a quality tire gauge to be safe. Low tire pressure can create more rolling resistance and will hurt your gas mileage. If you are not a good judge of tire pressure by looking at the tires, consider a cool new product on the market that replaces your valve stem cap. It shows green when your tires are at the proper pressure, and red when they are low on air.
Safe Driving,
Kevin Schappell
Posted: 2nd June 2006 | Author: Kevin Schappell | Category: Car Care, Fuel
How you drive can affect your gas mileage
We all like to race stoplight to stoplight, it’s a guy thing. But, did you know that nothing can affect your gas mileage more than your driving style? Studies have shown that you can save up to 33% on gas by altering your driving style.
Before we get into how you should drive for the best gas mileage, let’s talk about what you should do before you leave the driveway. The first thing you should do, if it’s hot outside, is turn off you’re A/C and roll down the windows. This will reduce the load on your engine, and clear out the super heated air that has built up in your vehicle. Once you are above 45 mph, roll up the windows and turn on the A/C.
We can now start our discussion on driving style and discover how you can save up to 33% on gas. The first thing to think about when driving is conservation of momentum. Consider the following two scenarios…
1. You are driving along at 45 mph and see a red light ahead. You wait until the last second and slam on the brakes, then accelerate away when the light turns green.
2. You are driving along at 45 mph and see a red light ahead. You let off the gas pedal, and coast into the light, while anticipating when it will turn green. If you time it right, you never stop and continue on your way, ahead of where you would have been in scenario #1
This type of thinking in scenario #2 will put money back into your pocket. Your brake pedal is your enemy when trying to get better gas mileage. If you can anticipate traffic ahead of you, and avoid having to push on the gas pedal hard, you will save gas. Any time you use the brakes, you are losing momentum and wasting energy.
I had a friend in high school, whose dad put a vacuum gauge in all of his vehicles. A vacuum gauge in simple terms, measures the load on an engine. It served to remind my friend’s dad how he was driving, and forced him to go easy on the gas pedal to save gas. Consider having your mechanic install one of these gauges, the cost is minimal, and you may learn a little about how you are driving. If you have a newer car with an advance engine computer, it may tell you your instant and average mileage. Use the instant gas mileage readout instead of a vacuum gauge, it’s just as good.
You want to accelerate as mildly and evenly as possible to get to your desired speed. If you have a tachometer in your car, you can watch engine RPM and try to keep it under 3,000. You should be able to get to your destination in a safe and speedy manner, using these techniques and save some gas in the process.
There has been a lot of debate about what is the best speed to drive on the highway. Politics and safety issues have clouded the issue even further. The fact is that every car has it’s own speed where peak efficiency occurs. I had a Corvette that got the best gas mileage at 70 mph. It’s not practical to drive this fast everywhere, so I compromised and kept it legal as often as possible. Depending on your engine, transmission and gear ratio in the axle of your car, you ideal speed will be higher or lower than my car. The most important fact to remember is to keep your speed steady and avoid abrupt stops and starts.
I have heard various automotive journalist report better gas mileage by not using the cruise control. There reasoning was that they were focused on driving for efficiency and could make better decisions that the cars cruise control computer. This theory is valid, if you are on a highway with a lot of elevation changes. If you are not using cruise control, you can allow your vehicle to coast down long hills and build up some extra speed, which will help you climb the next hill. Of course you need to use some common sense here and not allow your car to go too fast to avoid speeding tickets or dangerous driving conditions.
The last tip I can offer on driving, is make your vehicle as light as possible. The lighter your vehicle, the less you engine has to work to move you around. Remove any unnecessary items from the trunk and car to help keep your car as light as possible.
Posted: 2nd June 2006 | Author: Kevin Schappell | Category: Car Care, Fuel
Cracked Piston Replacement
Question:
It’s a lovely site and easy to understand for people who are not mechanically inclined. My garageman said one of the pistons is cracked and therefore he must change all the pistons. Is that true? Why not just change the one that’s cracked?
Thank you,
Mrs. A
Answer:
It is general practice to change all the pistons at once. If one piston is cracked, there is a good chance the others will crack in short time. When replacing the piston, the cylinder walls sometime need to be remachined, and at least honed, to allow the new rings to seat. It is important for the rings to seat properly or your engine will not have good compression and may burn oil. The labor to replace one piston or all of them is not much more, and the pistons are generally purchased in sets, so his advice to replace all pistons is good.
Kevin
Posted: 11th May 2006 | Author: Kevin Schappell | Category: Engine
Oil Change Disaster
Dear Kevin,
I am a Los Angeles Superior Court Mediator and I was hoping that you could help me with a technical question I have regarding a case I am hearing?
The case involves a litigant who took his car in for a 7-10 point check and a regular oil change (this being done before a long weekend driving trip). The party picked up his car, drove about 10 miles to his home and packed up the car and then drove on the freeway about another 20 miles until the car died. Knowing a little about cars, he checked the oil and it was bone dry, he proceeded to purchase 5 qts of oil and put it into the car, which took all 5 quarts. He then tried to start/run the car to no avail. Then had it towed and filed suit with our court.
My understanding is that the car would not have made it 1-2 miles without oil, not 30+? Is this true. It was also a cool evening (if that matters).
The car is a 1977 Pontiac LeMans (a classic and am told not many were made). The plaintiff also had the engine rebuilt just 5 months prior and it seems now, with some of the testimony I have in, that the engine needs to be rebuilt again.
Does any of this sound correct to you? I respect your opinion. The trial is Thursday so time is of the essence.
Thank you.
Respectfully,
Peggy R.
Court Mediator
Answer:
There are three possibilities that may have caused this situation…
1. The oil filter was not tightened properly and the oil slowly leaked out or
2. the gasket from the old oil filter was left on the engine, and when the new filter was installed, it caused a leak due to having two gaskets instead of one.
3. The drain plug was not tightened and fell out a few minutes before the engine seized. Any of the scenarios should be able to be proved by inspecting the underside of the engine looking for fresh oil indicating a leak, or a missing drain plug.
If the shop forgot to put oil in the engine, the car would not have made it more than a mile.
When doing an oil change, the mechanic should start the car, check for proper oil pressure (either on the oil pressure guage if installed, or by the absense of the oil pressure warning light) and check for leaks. Then check oil level after the engine has run for a minute or two.
Unfortunetly I have heard way to many stories of loose drain plugs, or loose oil filters from quick lube shops.
Take Care,
Kevin Schappell
P.S. We have a list of Online Oil Change Coupons updated daily for those visitors who use a mechanic for their oil changes. (Nothing wrong with that!)
Posted: 5th May 2006 | Author: Kevin Schappell | Category: Oil & Lubrication
Scratches after washing your car
Question:
Hi Kevin,
Your web site is fabulous – I googled “car washing” and your site was in the top three that came up. I have just spent 40 minutes reading through your various pages – great information.
Here is my question. I have a 2005 Fire Red Mustang, that just got its first wash after a few months of winter driving (I know, very bad to wait so long!). It is a lovely spring day in Vancouver and so I washed all the grime off my car. Some of the black tar like grime was very stubborn, and so I used the abrasive side of one of those two sided dish washing sponges to give them a good scrub. Not so clever as I discovered after I dried the car, now I can see whitish scuff like hazing in the paint where I did this.
I am hoping that all I did was scrub off the wax. I intend to leave the car in the garage over night to completely dry, and then wax it tomorrow – do you think this will remove those nasty scrub marks?
I hope I haven’t ruined my paint.
Thanks for your help.
Sandy
Answer:
Sandy,
You probably scratched the clear coat, which can be fixed. I would take it to a body shop and have them look at it, as it’s not an easy job for the beginner. They will probably use a cutting compound to smooth out the scratches, and then polish it to bring back the shine. I would not tackle the job yourself, as you may break through to the base color, then the only way to get the shine back, would be to respray the clear coat.
Good Luck,
Kevin
Posted: 5th May 2006 | Author: Kevin Schappell | Category: Body, Car Care
