Q: I use a 2012 Toyota Tundra with a six-speed transmission to tow a 6,000-pound trailer. Will gearing down (shifting to a lower gear) to control downhill speed harm the truck's transmission?

- F.G.

A: Every transmission shift adds a tiny amount of wear to parts within the transmission, but dropping a gear or two on long or steep downgrades, particularly when towing, is a very good practice and prevents the possibility of brake overheating.

Toyota recommends doing this by sliding the shifter left to the S, or sport, position and toggling it rearward for each intended downshift. On a downgrade where frequent braking is needed, I'd drop a gear - and another if needed - while keeping engine speed below 3,000 r.p.m. or so. The tow mode on my Chevrolet Silverado aggressively downshifts and holds gears when descending and climbing, more so than I care for, actually.

Trailer brakes can sometimes become overheated on long, continuous downgrades regardless of what you do with the truck's gears or brakes. Temporarily dialing back the electric brake setting can help with this, but be ready for a full-on manual lever push if trouble occurs. Trailers with surge brakes may benefit from the addition of a solenoid that can be intermittently activated to inhibit brakes at other times aside from when backing up.

Q: I read recently that the National Highway Traffic Safety Administration will appoint a monitor to oversee the recall of millions of Takata air bags. This recall will obviously take a while to complete. In your opinion, should drivers with these air bags in their cars electrically disconnect the bags to prevent their use? Pulling a fuse is easy enough. Essentially, are we safer with them or without them?

- Jim C.

A: This is a controversial subject. Takata, the Japanese maker of the faulty air bags, has stated that out of about 1.2 million deployments of its air bags over 15 years of regular driving, it is aware of 88 inflator ruptures that have occurred, according to Consumer Reports. That's a tiny percentage.

However, among recalled Takata air bags gathered from hot and humid areas - it's believed such conditions can contribute to inflator ruptures - and then tested in a lab, the rupture rate jumped to about 1 percent.

Were it my vehicle waiting for a new air bag, I'd consider the very slim likelihood of a deployment occurring during the next year (ditching the cellphone and driving extra carefully wouldn't hurt) and the 99 percent chance of proper operation should a frontal accident occur.

Disconnecting the bags is a giant hassle legally, and the appropriate method varies among vehicles. I wouldn't do it.

Remember the BMW a few weeks back with the lamp-out warning?

Jim P. writes back: "The high mount brake light was the answer. No socket melt. Just a bad bulb, and I replaced it."

Regarding an earlier column about a mechanism used to semiautomatically shift gears, Larry G. writes: "My best friend's father owned a 1937 Hudson Terraplane coupe. His car had the Electric Hand on the steering column. He said it hadn't worked in years so he used the floor shift. The Hudson was a good car. It was fast for its time with 102 horsepower. It easily outran the other kids' 60-horsepower '37 Fords."