Question: I regularly change my own oil and am wondering whether it's worth it to install a special oil-drain valve on my car. What are the pros and cons of them? And how come the auto makers don't put them on as original equipment?--A.T.
Answer: If there is one mechanical repair that most auto owners feel they can handle, it is certainly changing their engine's oil. The oil industry estimates that as many as 60% of motorists change their own oil, though other surveys put the figure at about 40%.
In any case, it probably comes as no surprise that changing oil can be a dirty and frustrating experience. For all of the advances made on new cars, the auto industry has done virtually nothing to make changing oil any easier for the millions of do-it-yourselfers.
You can blame cost as the main reason auto makers don't include oil-drain valves on cars. Although it would amount to only several dollars per vehicle, that would cost millions of dollars a year. And the industry figures nobody is going to care about changing oil when they buy a car.
As a result, an oil change means that you must wiggle under a car on your back and get an adjustable wrench onto a drain plug that screws into the oil pan.
On a lot of cars, these drain plugs are placed in the most inconvenient possible positions. Some Hondas, for example, have drain plugs that face the rear of the car, and getting a wrench onto a blind bolt head is a real trick. Some Toyotas have drain plugs that are guaranteed to drench your hand with oil, because they face straight up and you must use a socket wrench to remove them.
A Real Benefit
An oil-drain valve can be a real benefit to those who frequently change their own oil. Unscrewing a conventional plug and catching the plug before it drops into the oil drain pan is the dirtiest and most frustrating part of the job.
This is where a valve, which simply screws into the existing oil-drain hole, can really help. The best valves in my view are ones that have a small lever that can be opened and closed with one hand.
One drawback to most drain plugs is they reduce the size of the drain hole when they screw in. This results in a slight restriction, which traps some oil at the bottom of the pan. But it should amount to less than one-tenth of a quart--based on my calculations--which is not significant.
I had an opportunity recently to test one valve that recently came onto the U.S. market, made by Fumoto Engineering and available at many auto-parts stores at $10 to $15. It has a forged brass valve body and chrome ball seated between two Teflon ring seals.
The company says it has never received any reports of valves accidentally opening. Of course, that would ruin an engine and would be one source of concern.
I have also tested several other valves that I will not name. One valve requires a specially made plastic bag that collects the oil. That means you have to buy extra bags, which cuts into the economy of changing your own oil. It also encourages people to throw away their oil with their garbage, which is a really bad idea.
Old oil contains plenty of toxic stuff, such as lead, chromium and hydrocarbons, that shouldn't get into the soil. If I can offer one bit of advice on changing oil, it is to take your old oil to a gas station that will recycle it. Most stations are happy to accept the oil.
Ralph Vartabedian cannot answer mail personally but will respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, You section, The Times, Times Mirror Square, Los Angeles 90053.