Q: I own a 2011 Toyota Tacoma with 76,000 miles. Hoses seem to last much longer than when I began driving in the 1960s. As a preventive maintenance procedure, what is your rule of thumb for changing them?

A: The materials used to make hoses have come a long way since the Batmobile debuted. I have no mileage rule, but if you can squeeze the hose with your fingers, it probably is time to replace it. Ask your auto tech to give your vehicle the once-over from time to time.

Tranny issues

Q: My son has a 2011 Ram pickup with 163,410 miles on it. At 35 mph, the truck shudders. He downshifts to third gear, and it clears up. What could cause this?

A: The likely source is the torque converter. It connects the drivetrain to the engine with a lock-up clutch. If it fails to unlock at lower speeds, it shudders. By downshifting, your son is forcing the lock-up to release. Changing the transmission fluid might solve the problem, but you might ultimately have to replace the torque converter.

Trapped water a problem

Q: I have a 2022 Subaru Forester, and every time I go through a car wash or every time it rains, hours after or even days after, when I roll down the window, I put it back up and it is still wet. I am concerned that inside the doors this is going to cause rot and/or rust. Have you ever heard of this, and do you know of a fix?

A: Water sitting inside the doors is, indeed, an invitation to rust. That's why carmakers put weep holes in the bottoms. The weatherstrip sometimes obscures the holes and may need trimming. Use a small brush or pipe cleaner to also clean the holes.

Follow directions

Q: We just purchased a 2022 Mercedes-Benz GLC 300 SUV. We were told that we need to use premium gas (91 octane). But not all gas stations offer that. Many carry premium (93 octane) and plus (89 octane). Is there any issue with alternating premium and plus to average a 91 octane?

A: The carmaker's requirement is to use gasoline with a minimum 91 octane. Anything above that is fine.

Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician. His writing has appeared in automotive trade publications, Consumer Guide and Consumers Digest. Send automotive questions along with name and town to motormouth.tribune@gmail.com.