Motormouth: It's safe to ignore this warning light

Q: Every time I drive my Prius past the Thomas Jefferson National Accelerator Facility, the red triangle warning indicator lights up. This also happens to my wife in her Prius. Is this damaging the electronic components?

F.H., Newport News, Va.

A: Damage to your cars' electronics is unlikely. The red triangle is an attention-getter that usually combines with another warning light. Because your question is way above my pay grade, I posed it to Todd Satogata, senior staff scientist at the Jefferson lab in Newport News, and here is what he said:

"Jefferson Lab is a national laboratory full of science geeks who love nothing better than a good technical mystery. Jefferson Lab also has more than 700 employees, many of whom are Prius owners who would rebel en masse if there were any conditions near the laboratory that are affecting their beloved Priuses.

"None of several lab owners I surveyed have observed the red triangle light (known ominously as the Master Warning Light) come on regularly near the lab, but one did offer a possible explanation. One intermittent reason that the Master Warning Light comes on is because of low oil pressure, which can happen with a Prius in very stop-and-go traffic, such as is often seen in the heavy congestion on Jefferson Avenue, or during hard braking when you are slowing down to appreciate the excitement of a national lab studying the forces and structures inside atomic nuclei.

"In my experience, the acceleration of large vehicular traffic is far more dangerous to a Prius and its passengers than the lab's electron particle accelerators."

Q: We own a 2013 MDX Acura with 46,000 miles on it. We recently received a letter from Acura, Warranty Extension stating that the engine oil consumption exceeds client expectations. The original coverage is six years/70,000 miles. They've just extended it to eight years/125,000 miles, whichever one comes first.

With our present rate of driving, we will not get to the original warranty, let alone the extended warranty. The vehicle is serviced at the recommenced intervals by the dealer. The dealer indicates at this time that the vehicle is not using excess oil. We plan on keeping the vehicle for several years.

Obviously, we're concerned about the repair cost if it does burn excess oil after the warranties are up.

E.H., Maple Grove, Minn.

A: You are averaging roughly 10,000 miles per year, and by 2021 the engine will have about 70,000 miles. If your oil consumption has not significantly increased by then, your engine may not have a piston rings problem that led to the extended warranty. The issue is that the oil control rings may become clogged with carbon deposits. When that happens, the rings' ability to scrape and return oil from the cylinder wall to the crankcase results in excessive engine oil consumption.

Although your engine may dodge the bullet, I would still urge you to have a talk with the dealership principal, who may be able to go to bat for you should the problem arise beyond the new warranty. Carmakers like Honda are known to provide goodwill repairs.

Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician.