I am an old geezer who probably has lived through 100 or more oil changes in my lifetime, always using regular motor oil. Now I own a 2014 Honda CR-V that I bought used with about 10,000 miles on it, and it’s due for an oil change. The previous owner used synthetic motor oil. When I called the dealership to make an appointment, I asked about the difference between synthetic motor oil and regular motor oil. I was told that synthetic oil costs twice as much. For comparison, an oil-and-filter change using regular oil is $29.95. An oil-and-filter change using synthetic oil is $59.95. I also was told that synthetic oil is recommended for my vehicle. In addition, they claim that synthetic oil lasts longer, so you can go longer between oil changes. However, as far as I know, the computer-controlled oil-life indicator on the vehicle makes no distinction between regular oil and synthetic oil. In my generation, the $30 difference between the two is no small amount. Is synthetic motor oil really worth the extra cost?

I think it is. In my experience, and in legitimate testing, synthetic oil consistently performs better than dinosaur-bone oil. It lubricates better, makes engines last longer, improves mileage and takes longer to break down under the heat of engine use.

A number of supposedly informed people say you can go nearly twice as long between oil changes with synthetic. If you did that, the cost would be the same over the life of the car.

But you’re right that your car’s computer has no idea what you’re putting in the crankcase. You could put a kale smoothie in there, and it’d tell you it’s time for a new one after about 7,500 miles.

The “maintenance minder” system in your Honda keeps track of things like the number of engine starts and how many revolutions the crankshaft makes. And when it believes that your four and a half quarts of conventional oil is getting dirty, breaking down and needs to be changed, it lights up an indicator on your dashboard.

If you use synthetic oil, you’ll have to make your own decisions on when to change the oil and filter. You could go ahead and change the oil and filter when the light goes on, which is what Honda would tell you to do, and accept that you’re just paying that extra $30 to get better engine protection and longer engine life. I’d be tempted to do that, too.

Or you can ask the Honda service manager for his or her recommendation. And ask him to make a note on your oil-change repair order when you’re due for your next oil change, given that you’re using synthetic oil. That way, Honda can never challenge you if you need a warranty claim someday by saying you didn’t change your oil as often as Honda recommends.

If it were my car, I’d use the synthetic oil and pay the extra $30. Using good, clean oil is one of the cheapest insurance policies you can buy for your engine. So, don’t think of it as a wasted $30. Think of it as a great deal on engine insurance.

I would like to purchase a used luxury sedan from the 1960s (Lincoln, Chrysler or Cadillac). Many are advertised with rebuilt engines. Do you have any experience or knowledge about the reliability and dependability of these rebuilt V-8s? Could I expect one to run 75,000-100,000 miles without major problems if it is not abused? Thank you.

Sure. Keep in mind that when these cars were new, if you got 75,000 miles out of the engine without major repairs, you’d be thrilled. And it’s unlikely that they’ll be any more reliable or dependable than they were in the 1960s. That means they’ll be prone to flooding, stalling and not starting in the rain.

You can improve reliability by converting the thing to electronic ignition. There are companies that sell kits for doing that.

But in general, mediocre reliability is the price you pay for falling in love with something old and unusual. Just ask any of my brother’s ex-wives. Of course, if your top priorities were reliability and dependability, you’d be looking at a 2011 Camry and not a ’60s Lincoln.

So to answer your question, if an engine rebuild is done well, the engine absolutely can last many tens of thousands of miles.

And if you really plan to keep the car for 75,000 or 100,000 miles, you should consider finding a good car that you like, and then having the engine rebuilt yourself. That way, you’ll know it’s been done well, and you’ll get the maximum life out of it.

A guy I know brought a ’59 Cadillac convertible into the shop to have it restored. We obviously couldn’t buy a new engine for that car, so we sent the old engine out to our rebuilder of choice, Jasper Engines.

We removed the engine, stripped all the accessory parts off it and shipped it to their rebuilding factory. They re-bored the cylinders, put in new pistons, reground the crankshaft, replaced all the seals and gaskets, and then shipped it back to us.

We put all the external parts back on it, dropped it back into the Cadillac, and it runs beautifully. Our customer has been driving it ever since.

Now we’re just counting the days ’til he comes back in for a rebuilt transmission.

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