QUIKAG

My Vibe's 2ZZ motor has an 11.5:1 compression ratio, the C5 has an 10.5:1 CR.

I believe the M3 has an 11.5:1 compression ratio.

Anything higher than that? What does the S2k, 360 Modena, etc. have??

steve c

Without a doubt something the diesel family, where ratios in excess of 20:1 are not uncommon.

Regarding gasoline engines, here is an interesting read of a 1.6 liter SAAB motor outputting 150hp/liter utilizing varying compression.

http://waw.wardsauto.com/ar/auto_variable_...pression_small/

QUIKAG

I knew someone would bring up diesels. I was specifically referring to gasoline engines, though I guess I didn't specify..

I read about the variable compression Saab motor a few years ago. Why hasn't it seen production yet?

lanbrown

For several reasons, reliability, expense, size and emissions.

The pre-2004 S has 11.0:1 and the 2004 has 11.1:1.

cfusionpm

my dsm's have 7.8:1 and 8.5:1

mxt_77

Ferrari 575GTC is 12.9:1
Don't know if it's street legal, though as it's advertised as a "competition" car.
Most of the other Ferraris are around 11:1.

mxt_77

Ooh.. and the Porsche GT3 is running 11.7:1. May not beat the race-prepped Ferrari, but it edges out your Vibe.

Mr Payne

575 GTC.............no way street legal.

QUIKAG

[QUOTE]Originally posted by mxt_77
Ooh.. and the Porsche GT3 is running 11.7:1.

mxt_77

[QUOTE]Originally posted by QUIKAG
Speaking of which, is the 2ZZ the highest compression motor that is also the slowest?