Turbo Tips: Five Ways To Extend Your Turbo's Life
Turbocharging is enjoying a second renaissance thanks to its one-two-punch of power and fuel economy.
Whereas regular ("naturally aspirated") engines rely on size or high RPMs, turbocharged motors deliver power in compact packages and torquey-punch at lower engine speeds.
When you put your foot to the floor, the increased load churns out exhaust pressure — spinning the turbine (which spins the compressor-side of the turbo via connecting-shaft). That allows a smaller engine to suck in as much air as a larger one.
Mix the extra air with extra fuel, and the smaller turbo engine makes more power than it could alone. Keep the turbo at arm's length and the engine operates as frugally as its smaller size allows. This magic and wizardry does come with added responsibility to car ownership though.
Turbocharged cars have added complexity in their design, with additional parts to potentially fail. The turbo itself requires a bit of vigilant care, lest you incur expensive repairs.
Here are five ways you can help extend the life of the turbo in your car.
Regularly Scheduled, Synthetic Oil Changes:
Oil (and changing it regularly) is already crucial to an engine's longevity. It's invaluable to the life of a turbocharger. The firsts turbos were solely oil-cooled, supplied by the engine's oil.
Today's turbos are additionally cooled by coolant — but are still harsh on oil.
Fully-synthetic oil is the safest bet, protecting well from the high temperatures of turbo-life. You can check your owner's manual for recommended oils, but if that's long gone (or the specified oil isn't sold near you), check online-forums of enthusiasts for compatible blends.
Whichever synthetics are recommended for your turbo engine, 5,000-mile oil changes are a comfortably safe margin. BobIsTheOilGuy.com is a marvelous source of oil information. Members share oil-sample tests for truly empirical reviews of the stuff in their engines.
If you're someone who barely uses the turbo, some BITOG.com users have extended intervals to 7,000 miles or more (but they're checking their oil for wear-levels fastidiously when choosing an oil and how long to use it).
Warm It Up:
Supplying your turbo with fresh oil frequently is a start, but once it's in your engine — you have to use it properly. Oil functions its best within an optimum operating temperature. It flows and lubricates the best when around 190 to 220 degrees Fahrenheit. Prior to that, its thicker state increases oil pressure — putting more strain on oil seals.
The seals of a turbocharger are located in its central cartridge, where oil lubricates the shaft that connects the turbine and compressor sides. When these wear enough to let oil seep excessively (a bit of oil "blow-by" is normal in a turbo with some use), you may see excessive blue-like smoke from the exhaust.
Getting the oil up to temperature also burns off moisture that builds in it while it sits cool in the oil-pan. Quick, short trips taken frequently will necessitate an oil change sooner because the fluid will become saturated with un-burned impurities.
A good rule of thumb is once the coolant temperature is up where it belongs, the oil will take another 10-minutes of steady driving to follow suit. Before then, it's ideal to take it easy on the go-pedal.
Cruise Right, Cruise Light:
Once warmed up, turbo cars are rarely boring.
Boost gauges are often smile gauges; the slingshot effect of when turbos spin up and catapult the car ahead is as infectious as the flu. Use it judiciously though.
There's no need to fear the car is made of glass. Auto makers today put their engines through crucible-like tests to be sure that only regular irresponsibility causes critical early failure (for the most part). European turbo-cars (especially those from Germany) are tested to maintain Autobahn speeds for sustained periods of time. You just have to exercise simple warm up and cool down habits to pay the engine back.
When you don't want to cane the car and are driving regularly, try to be sure you're working the engine as little as needed. On my car, maintaining the boost/vacuum gauge between 10-to-15 In.Hg (inches of mercury) is the minimum amount of engine force necessary to sustain speeds in top-gear. The turbo is far from being used, reducing wear — and increasing gas mileage.
Without a boost gauge, the simplest way to do this yourself is to keep an eye on your speed when cruising. Begin letting off the gas slowly until you notice your speed begins to drop. The moment you notice you're slowing, gently tip into the gas again until you maintain speed.
That is the minimum amount of gas you need to cruise (you may find out you were applying more gas without any added acceleration, just added consumption).
Cool It Down:
If you just got home from a grin-making, fun drive (or have been cruising at highway speed for a couple of hours) — don't turn your turbo-car off immediately! Unless your last couple of miles were driven gingerly, the turbo will likely be hotter than ideal for shutting the engine off.
The reason for this is because of that lifeblood-oil coursing through it. If it's not given proper time to circulate and cool, the oil cooks into sludge – and clogs the oil channels. When sludge blocks the cooling channels of the turbo, insufficient lubrication will wear its bearings faster.
A minute of idling time after a 20-to-30-minute drive is a bit of added prudence (around two minutes after long or hard drives, like laps at the track).
Programmable "turbo-timers" are available for purchase, able to set times for idling the engine without the key in the ignition (security features like sudden-shutdown when keyless driving is detected are available). This bit of anal retentiveness can be worth hundreds to thousands in avoided early turbo failure.
Work the Gears, Not the Turbo:
If you have control of gear selection in your car, selecting a lower gear for cases like passing or climbing a hill can spare the turbo doing all the work.
Being a gear or two lower reduces the amount of times you have to utilize maximum boost pressure — whether for short bursts or relatively longer. Regularly keeping the turbo howling to avoid a downshift up inclines can pop your turbo-bubble (quite literally).
A lower gear puts your engine further into its "power band", the span of RPMs in which it works the most efficiently. In those ideal engine-speeds, less throttle (and boost) is required than in higher gears.
Liken this to picking up a heavy bag by its strap with one finger.
Your hand, wrist, and arm may all be capable of lifting that bag effortlessly, but your finger would have to work hard to do it alone. There's more to a turbo car than just the turbo, utilize it.
Turbo repair and replacement is a costly process — even if done by yourself.
If you're paying for the skilled hands of another to do it for you, everyday maintenance like this will seem much easier in hindsight. Steps like these are just some of the simplest ways to decide if the turbocharger in your car lasts 18,000 miles – or 180,000 miles.