Dear Car Talk:
I like to drive small SUVs and want to get a new one. It seems like most of the engine offerings are turbo models (better gas mileage for the government). Are turbos reliable for the long term (120,000-plus miles)? I heard that they require special maintenance, like cool-down periods after a hard drive, but my mechanic says they resolved that issue. Have they? Are they still expensive to repair? Would you recommend them? -- Doug
Yes, yes, yes and yes.
A turbocharger is a turbine fan powered by the car's escaping exhaust gases. When the exhaust gases blow past the turbo, it spins at a ridiculously high speed and forces fresh air into the cylinders. That increases power, but increases fuel consumption only while you're demanding that power -- rather than all the time, as a larger engine would.
In the early days of turbos, they tended to last about 75,000 miles before failing in a dramatic cloud of black smoke. That was great for those of us in the repair business, and helped me put my kids through college.
Turbos usually failed, because they ran so hot that oil would get dried up in the small oil passages and eventually constrict those passages and prevent the turbo from being lubricated. That's why it was recommended that, after a hard drive, you allow the turbo to cool down before shutting off the engine. But your mechanic is right that that's no longer recommended, nor necessary.
Both turbos and oils (particularly synthetic oils) are a lot better now, making turbos infinitely more reliable. We've seen very few turbo failures lately. Thank goodness my kids have already graduated.
Almost every manufacturer is using turbos now. And they're doing exactly what they promise to do: They provide more power from a smaller engine, reducing weight and, therefore, increasing fuel economy.
Will a turbo you buy today go 120,000 miles? Probably. It could go 220,000 miles. But like any mechanical part of an engine, there's no guarantee. And any major engine component -- a cylinder head, a timing chain or a turbo -- will be expensive to repair if it does fail. So if you're uncomfortable with the idea, don't get one.
But I wouldn't hesitate to buy a car or small SUV with a turbo these days, Doug.