Added Gas And Oil Conditioners Deserve Some Questioning

Dear Car Talk:

I went to my Toyota dealership to get my 2021 Tundra's oil changed. They use synthetic oil. The cost for an oil change and tire rotation was $195. Over $60 of that was for "oil conditioner" and "gas conditioner." Synthetic oil is expensive enough -- do I really need oil conditioner?

I've been a long-time customer. This time, I'm feeling a little duped. They didn't use "oil conditioner" during the free maintenance period, by the way. -- Nelson

I've heard that oil conditioner makes your oil easier to comb, style and blow dry, Nelson.

These sound like profit conditioners to me. I'd ask what purpose these additives serve. I'd be curious to hear the dealer's answer.

Many years ago, Subaru was having a problem with oil burning. And as a solution, Subaru recommended an oil additive that supposedly reduced the oil consumption. So, I suppose something like that could be going on. But if that's the issue, they should be explicit about it. And I've heard nothing about any such Toyota directives for late-model Tundras.

The gas conditioner is even more questionable. Eons ago, people used to add gas line anti-freeze to their fuel tanks. It was essentially alcohol, and any water in the system would bind to the alcohol and then get expelled during combustion. But the need for that was eliminated decades ago when alcohol was added to gasoline itself.

"Gas conditioner" could also be some kind of fuel system cleaner. You don't need that either, because there are very good detergents in gasolines already.

Then there's gasoline stabilizer, designed mostly for lawnmowers and snowblowers that sit for much of a year without running. Stabilizer helps prevent old, inactive gasoline from degrading and leaving varnish deposits. But you haven't said anything about letting your Tundra sit for 10 months at a time, Nelson.

So, I'd ask the dealer to explain exactly what these conditioners are, what they do and why they're necessary. And when he can't, or can't do it convincingly, decline them both next time.

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