ArcaMax

So the car companies pushed for - and got - major reductions in the ZDDP mixed in with commonly available engine oil. Which most people don't have to sweat because most people do not own cars that are 30-plus years old.

But if you are among the few who do own a car that's 30-plus years old ... well, you have a problem. Or will - if you use off-the-shelf oil that lacks the necessary additives.

And it's not just a wear and tear issue, either. Cars 30-plus years old tend to sit a lot because they're usually not used for everyday driving. My '76 Trans-Am is probably pretty typical in that I take it out once or twice a month and drive it for about half an hour or so each time. This keeps the miles low - and when not running, of course, there's little wear and tear going on, ZDDP or no ZDDP.

But when it's just sitting, condensation (moisture) forms inside the engine. Oil and water - not good. Also, older cars typically have carburetors and they tend to leak gas into the engine. Gas is a solvent. Washes the oil off metal surfaces that rub together. Also not good.

I use Amsoil Z-Rod oil in my old muscle car because it has the anti-friction additives (ZDDP) its engine needs (particularly because my engine has been modified with a more aggressive camshaft, which means more aggressive cam lobe profiles and more pressure/stress exerted on the lifter's flat base) and also because the stuff is specifically formulated for engines that do a lot of sitting. It has corrosion inhibitors not found in over-the-counter "mainstream" oils - which, remember, are formulated for modern cars with roller-type camshafts and fuel-injected engines.

Now, there are other high-quality synthetics out there (Royal Purple, Mobil1) and you can buy a bottle of ZDDP additive to mix with them. But I like Amsoil because it does not require the purchase of additive - and because it is formulated for the usage (and non-usage) patterns typical of "retired" vintage vehicles. I also get away with changing the oil just once a year - due to the extended drain intervals Amsoil recommends - which ends up saving me money over the long haul.

Also because Amsoil sells high-performance filters to go with the oil. Beware cheap (and made in China) oil filters. They even have filters for long out-of-production engines like the 455 in the Great Pumpkin!

Final tip: I always refill the individual quart containers with the old oil just drained. This lets me keep precise track of oil consumption since the last oil change. If your car usually uses say a quart of oil in between yearly oil changes and this oil change you discover you've only got enough old oil in the catch pan to fill up four (out six) of the quart bottles instead of the usual five or so... it's pretty solid evidence your engine's either developed a leak or it is using more oil, the latter indicative of a mechanical issue you'll want to look into. Either way, you'll have an early warning - to check the dipstick more frequently.

Which could save your classic car's engine from an early (and unnecessary) demise.

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www.ericpetersautos.com or EPeters952@aol.com for comments.