What's stock compression ratio?

[Randy 25]

What is the stock compression ratio of these 4.6 engines? Any difference between 05 and 09 that anyone is aware of?

 

[Five Oh Brian]

2009 Mustang GT's 4.6L V8 has 9.8:1 compression ratio according to the Ford SourceBook.

 

[walter]

wasn't it something like 10.0 or 10.3:1 I thought it was pretty high and unsuitable for F/I when I first heard of it.

 

[partsbill]

2005 / 2009 = 9.8:1