Also, is there a big cost differential vs. air inflation? — Gregory
Dear Gregory: I don’t want to go so far as to call this a scam, Gregory, because scam is a very strong word. But it’s really close. So, let’s go with “unnecessary upsell.”
There are some tire shops these days that are charging people to fill their tires with nitrogen rather than “air.” But keep in mind, air is 80% nitrogen.
Now, they cite some reasonable sounding arguments for why you might want to use 100% nitrogen rather than 80% nitrogen and 20% oxygen — known as air. For instance, they say if your car catches fire and your tire explodes, nitrogen — an inert gas — won’t feed the fire. What they fail to mention is that there’s an infinite amount of oxygen all around the tires, in the air. So that’s nonsense.
They’ll also tell you that nitrogen-filled tires don’t change pressure as much as air-filled tires when your tires heat up and cool down. This is true, but it hardly matters. The normal range of pressure variance while driving is of no consequence to most people. If you’re driving a Boeing 777, yes. But not a Nissan Versa.
Some customers have been told that nitrogen-filled tires will leak less than air-filled tires because nitrogen molecules are larger and can’t get through the rubber as easily.
Well, very little air (or nitrogen) ever seeps through the rubber. When you have a leak, it’s usually due to a puncture, a bad valve or a rim issue. And both air and nitrogen will leak out if you have “a leak.”
And finally, one pitch for nitrogen says that it’s less likely to degrade the inside of the tire the way oxygen can. OK, fine. But what about the outside of the tire? The part that’s constantly surrounded by air that’s 20% oxygen?
So, if you add it all up, unless you’re landing a plane or driving an F1 race car, it’s hard to come up with a scenario in which it’s worth paying extra to have your tires filled with nitrogen.
Maybe try helium. Then at least you can entertain the kids at their next birthday party.
Dear Car Talk: My daughter’s 2018 Honda Pilot LX’s warning light came on, so she took it to the dealer. They said there were metal shavings in her transmission fluid so they flushed it. Then they said she needs a new transmission for $7,500 or they can sell her a new car, because her transmission could seize up at any time.
They also said she needed new tires. All four were just replaced a year ago. The car has 86,000 miles. Does this sound reasonable? Her car has had no performance issues, just the warning light. — Cheryl
Dear Cheryl: You need a second opinion, Cheryl.
The fact that they tried to sell you a transmission, four new tires a year after they were replaced, and a new car, suggests that their first priority may not have been trying to save you money.
The metal shavings don’t necessarily mean your transmission is toast. All transmissions have small amounts of metal shavings in them from years of gear meshing. So, unless they removed enough shavings to open an aluminum foundry, that doesn’t give me a lot of information.
And you say the car has no performance issues. There have been transmissions failures on Honda Pilots and Odysseys of this era (there’s even a class action suit), but those transmissions tended to exhibit drivability issues, like “juddering” on acceleration or slow shifting.
It’s possible that you do have a bad transmission, but I’d start by getting a second opinion. If a second mechanic you trust agrees, then the next step is to go back to Honda and ask them for some help.
It’s true, your car is out of warranty. But hopefully, they would agree that a Honda transmission shouldn’t fail on a car that’s 5 years old and has only 86,000 miles on it. Tell them you’ve been a good customer, and given the car’s age and mileage, you’d like to request that Honda “participate” in this repair with you. Tell them if they help you out, you’ll even agree to buy the four tires you don’t need.
They might offer you a discount. Or they might invite you to buy a Toyota next time. But while you’re waiting for their answer, you can shop around and get some other estimates.
If your transmission is failing, you may be able to get it repaired or replaced for less than what the dealer quoted — at Honda or somewhere else — and then, hopefully, drive it for another 86,000 miles. Good luck.
Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.
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