Why is oil so important to turbochargers?

Why is oil so important to turbochargers?

Turbochargers have transformed the performance – to say nothing of the image and appeal – of diesel powered cars. What were once considered smokey, oil-burning ‘rattlers’ have become refined, high performance machines that now command over 50% of new UK car registrations, thanks at least in part, to the ‘civilising’ impact of modern turbo technology.  

Today, nine out of ten diesel passenger cars are fitted with a turbocharger. Combined with sophisticated engine mapping and diesel particulate filters, they increase power and contribute to lower exhaust emissions, as well as delivering 20+% better fuel economy and superior torque characteristics when compared to petrol engines of similar displacement.  Currently, around 24% of all cars – diesel and petrol – on UK roads are fitted with a turbocharger. That’s forecast to be no less than 70% by 2020, and makes turbos a big issue for the independent aftermarket technician.

Turbochargers are mechanically very reliable, with only 1% of failures attributable to a manufacturing fault with the turbo itself. That said, the alarming statistic is that over 90% of turbocharger failures are oil related!

Which is perhaps unsurprising, when you consider that a turbo’s rotating components spin at up to 240,000 rpm – that’s 4000 revs per second – and have to endure extreme constant exhaust gas temperatures of up to 950°C.

In conditions like that, the turbo shaft and bearings are under immense stress, and totally reliant on the protection provided only by a thin film of the correct oil as specified by the vehicle’s manufacturer. If these parts are starved of oil, the turbocharger will almost certainly fail under load in a matter of seconds.

Similarly, if the oil is contaminated for any reason, or if entirely the wrong oil is used, the shaft and bearings can quickly degrade through scratching, scoring and/or excessive wear, and it will be only a matter of time before they give up the ghost.

And that’s when things get really expensive, because the latest generation VNT (Variable Nozzle Technology) turbo cannot be reliably repaired; replacing and fitting a new one can easily set you back over £1000

So, to give service technicians and their customers expert advice and guidance on how to avoid costly turbo failure and replacement, Comma is working in association with the world’s largest independent turbo distributor, BTN Turbo Ltd.

To start with, you can make sure that you’re using precisely the correct oil for any given turbo by using the vehicle registration look-up function at www.CommaOil.com. For your peace of mind, every recommendation carries Comma’s 100% guarantee: just make sure you use – or supply your customers to use – the exact same Comma oil when topping up between complete oil change intervals. In addition, backed by BTN Turbo, Comma has produced a series of leaflets for you and your customers that explain how turbos work and why getting the right oil is so important.

For more information: enquiries@commaoil.com or www.btnturbo.com