Road resurfacing creates annoying driving conditions

QWhile my question isn’t related to the mechanics of my car, it is related driving. This past summer I drove on several roadways only to discover that road crews cut the road, making annoying rumble strips, sometimes for long stretches. Was wondering if you could tell me what they are doing.

K.G., Saylorsburg, Pennsylvania

AWhat you describe is milling. The first couple inches of the road surface is removed in preparation for a new surface. Although it feels weird, the surface neither damages nor reduces the life of tires. The ground-up asphalt is hauled away and usually recycled to become new paving material.

QI’m a light-footed original owner of a 2017 Subaru Impreza with 24,000 miles. I had a recent recall, oil and filter change and general inspection visit to my Subaru dealership. During that visit the technician sent me a neat walk-around video inspection of my vehicle. In it, he recommended complete fuel induction and throttle body cleaning to prevent carbon buildup on intake valves. Estimate: $145. I refused the service. In your opinion, was this recommended fuel system work, with no other indications than mileage, a good idea?

J.J., Virginia Beach, Virginia

AUnless you have been using cheap, no-name gas, the intake valves probably don’t need cleaning. But throttle body cleaning is a legitimate service and the fuel injectors may get clean too. The quote was not out of line, so I suggest you approve the service next time you have the oil changed.

QJust wondering: Why don’t car manufacturers tint windshields the way eyeglasses are tinted for transition lenses? C.R., Milwaukee

AThe U.S. Department of Transportation has strict regulations regarding windshields. For instance, the tinted portion of the glass may not extend below the 12-A line. (Look for it on the upper right corner of the glass.) I have a hunch that transition technology, no matter how convenient for the driver, would never get approval.

QMy 2014 Highlander has 161,000 miles on the original spark plugs. The car runs fine and is getting 22 mpg with a V-6. Your thoughts on changing the plugs as my service guy recommends.

R.Z., Mokena, Illinois

AThe replacement schedule for platinum tipped spark plugs is generally 100,000 miles. You may not feel much difference in performance, but a fresh set of plugs may improve starting, especially in colder weather. It’s not cheap, but worth doing.

QI have a 7-year-old Buick LaCrosse with 80,000 miles. During an oil change the mechanic indicated a rear main seal leak as a “caution” item.

The service writer at the dealership and a NAPA clerk both said that it was not a problem at this time. (There’s no oil spot on the garage floor and no noticeable oil level drop between oil changes.) The price quoted to repair was $4,600 or almost half the value of the car. What is your opinion of the situation?

D.S., Orland Park, Illinois

ABoth your mechanic and the parts store guy are right—at least for the time being. The fact that you see no oil on the floor is proof. Yet when the seal begins leaking, it does so mostly while driving. That’s when you will begin seeing evidence. At the first sign of leakage, use some rear main seal leak stop. It could buy you some time. Keep up with your oil change schedule.