[ar5boosted]

Originally Posted by 14'ecocruze

Been peaking in on this thread time to time. I have never truly understood why the turbos have lower compression. Why not keep the compression the same? Probably a dumb question but there it is lol

Well you are right in what you are thinking. That's because they were configured for more power.

Let's say you want to increase a 2L engine from 125hp to 250hp. To do that implies that you need space in the combustion chamber for twice as much air.

So you'd lower compression to allow for twice as much volume of air. Because you must otherwise the engine will explode.

Lot's of these new fuel-efficient engines don't really run lower compression engines at all although they are turbo-charged. In addition, the turbo doesn't really add a lot of power. The amount of power they actually add would be traditionally considered as pitiful. Typically it's only 30-50%.

However, the turbocharger is to be technically accurate, adding another two cylinders to the engine. [The inlet and outlet chambers of the turbo are technically speaking a cylinder each].

So a typical 3-cylinder 1.0T engine is actually a 5-cylinder 1.0 engine. A four-cylinder 2.0T is actually a 6-cylinder 2.0 litre engine.

[Doing my best to follow what the Europeans are up to]