Everyone who has a 5th generations:

Does someone know what the compression ratio is for the engine, someone said 9-1 is this correct??

thank you.. Bernie

 

Unless I am very incorrect, the VQ30DE and VQ30DE-K both had 10:1 compression.

 

What is compression ratio-- or what does does it do?

 

Hmm, how to explain this.... It's the ratio of the cylinder volume when it is at 'Bottom Dead Center'(which it would be at the end of an intake cycle) to the cylinder volume when it is at 'Top Dead Center'(at the start of the combustion cycle.)

 

Or, in other words, how much the air/fuel mixture gets compressed during an engine cycle.

 

Compression ratio is the volume above the piston at BDC (bottom dead center) divided by the volume above the psiton at tDC (Top Dead Center. Basically it tells you how much air fuel mixture will be compressed when the engine is in its compression stroke. The higher the compression ratio the more power an engine can produce, In theory, that is. This is out of my automotive tech book but in my own wording because theres more in the book.

 

thanks...

 

Hmm, the first 3 sentences look familiar.

 

Maybe because we were both typing the info at the same time only you finished first.

 

Menacer's explanation was superior to yours.