Dear Car Talk:

I have a 2010 Ford Ranger that I use as a second vehicle. It's also on the "friends and family plan": It seems everybody needs help with a pickup now and then. It has only about 12,000 miles and probably is not going to get many more per year. I have the oil changed about every 18 months or 2,500 miles. Now the dealer wants to start changing the fluids. Which ones are the most important and would be cost-effective to have done? I am 75 years old and will need the truck for another five years or so, but I do want it to be dependable for that time. What fluids should I have changed, and which ones can I let slide? Thanks, and I enjoy your column each week.

-- Mike

My pickup truck was on the "friends and family plan," too, Mike. That's why I got rid of it. It seemed like every weekend I had to help some distant acquaintance move a refrigerator.

Anyway, at 75, I'd be more concerned about getting your own fluids checked than this truck's fluids. I don't think you need to change any of them, except maybe the brake fluid.

Brake fluid can attract water over time, and that can lead to rusty, and then leaky, caliper pistons and wheel cylinders -- especially when combined with infrequent use. So after six years, I'd say a brake-fluid change is a good idea.

Other than that ... I'd probably change the oil and filter once a year instead of every 18 months.

But things like coolant, differential fluid and transmission fluid probably all are good for 100,000 miles on this Ranger. And at the rate you're adding miles to this truck, you won't get there until 2085. So, in 2085, change everything.

But given your super-low mileage, the only fluids you should need to worry about for now are brake, gas, oil and windshield washer.