Motormouth: Lube suggestions for balky car door

Q: I have a 1994 GMC pickup. When it gets cold it is very hard to unlock the driver's door. A couple of times I have had to unlock the passenger door to get in. We tried spraying WD-40, but that hasn't seemed to help. What could I do to make it easier to get into my driver-side door in the cold?

R.F., Brooklyn Park

A: Although WD-40 is magic stuff, it is not the best choice to lubricate automotive door locks and linkages. Although it does a good job of cleaning and temporary lubricating, it goes away, so it makes a good first step. Graphite has long been a popular lube choice, but we like to use bike chain lube. Many of our readers and locksmiths swear by Tri-Flow lubricant.

Q: I constantly have to put air in the tires. The service adviser says this is because I have alloy rims and they corrode due to salt usage in Minnesota. Is this legitimate? They will clean the rims at a cost of $35 each, which I think sounds exorbitant, and wonder if this is something that Ford should correct.

M.V., Columbia Heights

A: It is true that salt and alloy wheels are often a problem. Since this is not a factory flaw, the car company will not work with you. And it is not only Fords that have the problem. One solution is to buy a set of steel wheels and mount winter tires on them. Store the alloy wheels until spring arrives.

Q: Is it true that eventually, all moonroofs will leak?

A: It is not true, but the onus is on you to perform regular maintenance on the windows. First, avoid parking with the sunroof open where dust and leaves can get into the drains and clog them. Second, apply silicone to the rubber seals at least once a year to keep them supple and reduce the chances of tearing. Third, keep your glass clean.

Q: I own a 2015 Chevy Silverado 1500. My truck came with basic wheels and hubcaps and I want to upgrade to 18-inch aluminum rims. The truck came with 17-inch rims. What has to be recalibrated to compensate for speedometer, odometer, etc.? I am getting conflicting answers from mechanics and dealers.

B.R., Lisle, Ill.

A: You will have no issues with the speedometer, odometer or ABS system if you maintain the original wheel-and-tire diameter. That involves installing lower-profile tires on the larger rims. In this case, you would probably need to go with 275/60-18 tires.