Eric Peters is the resident car expert on LewRockwell.com.
Recently, he wrote an article on maintaining old cars. He spoke of his 1976 TransAm.
I still have all the original paperwork, including the service schedule. It tells me to change the oil once every 7,500 miles or six months — whichever comes first. Well, it’ll take me at least a decade to rack up 7,500 miles — since the car only leaves the garage occasionally. I drive it about 500 miles each year.I should probably change the oil more often than once every ten years.
But once every six months? Given maybe 250 miles or so of driving? That seems . . . wasteful.
Expensive, too. Oil — the good stuff — costs more than $10/quart and the old Pontiac takes six. Plus a filter. Plus tax — and it’s about $75 to change the oil . . . myself.
But the oil does need to be changed at some point. So — what point? I split the difference and do it once a year, regardless of the mileage. Even if the car has barely been driven at all.
In fact, precisely for that reason.
Not because the oil wears out. Oil is pretty much eternal, actually. But it does become diluted and contaminated, especially if it’s sitting in the crankcase of an old car with a carburetor perched on top. These invariably leak gas, which finds its way into the crankcase, where it dilutes the oil. And gas is not a lubricant. It is a solvent. This is not what you want mixed in with your lubricating oil.
There is also condensation — water — that mixes with the oil. Also not a lubricant. And, sludge — the bane of lightly/rarely-used cars. It can gum up the works, including the oil pump pick-up, which is usually located in the bottom of the oil pan. If the intake screen gets glutted up with the internal combustion equivalent of chunks of cholesterol . . . well, the results are actually kind of the same.
Which is why I change the TA’s oil once a year, no matter how few miles it’s been since the last oil change. I take it for a half-hour drive first, too. In order to thoroughly warm the engine so that the hot oil carries with it as much stuff-I-don’t-want in the crankcase out with it as possible when the drain plug is removed.
And I use synthetic oil (Amsoil, usually) because of the superior protection it provides, especially in a car that sometimes sits for weeks at a time. Synthetics stand up better to that kind of duty, in particular, the thin lubricating (and protective) film on critical wear surfaces such as bearings, cylinder walls and camshaft lobes.
I recommend that he stop doing any of this. He should never change the oil again.
Peters is a rarity. He understands that oil does not wear out. I have been told by self-appointed automobile oil experts for about 50 years that oil wears out. They don’t know what they’re talking about.