Owner's manual versus sage brotherly advice?

Dear Car Talk

Dear Car Talk | Jul 01, 1991

Dear Tom and Ray:

The owner's manual of my 1988 Chevy Nova recommends limiting my maximum speed during the first 200 miles (which I did.) My brother, who is a mechanic in the Navy, says that's a bunch of baloney. Who's right?
Mary Jo

RAY: You're right, Mary Jo. I haven't seen an owner's manual for a Trident Submarine, so I don't know what kind of break-in period they require. But if the Chevy manual says to limit your speed, that's what you should do.

TOM: "Breaking-in" a car is a lot easier than it used to be. You used to have to follow an elaborate set of rituals. You had to drive slowly for a thousand miles, you had to vary your speed every few minutes, and you had to kneel down after dinner and pray while facing Detroit.

TOM: You did all that so the rings would "seat" correctly, and the car wouldn't burn oil before it's time. But now, engine tolerances (the spaces between moving parts) and engine oils are so much better, that far less care is needed when the car is new. In fact, some manufacturers require no break in period at all anymore--they skip right to the break down period!

RAY: But Chevy obviously believes that moderate driving during the first few hundred miles will inprove this engine's longevity, and they're probably right. It certainly won't hurt to be gentle to the engine when it's brand new. So you did absolutely the right thing by following the manufacturers instructions.

TOM: And I hope your brother is better at following the instructions of his superior officer than he is at following the instructions in an owner's manual.

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