[Fraser]

I have a 2008 Ford Mustang GT Convertible. If I converted to run on natural gas of course I would get less gas mileage and less power. But natural gas has an octane rating of about 120 so I modify the engine to take advantage of that high octane rating by increasing the compression ratio.

 

[roselyn]

I know your GT is 6cyl, but tests at different speeds and loads were carried out with a natural gas fueled, 16 valve DOHC (dual overhead cam) two-litre four-cylinder engine representative of current passenger car design. Compression ratios of 10.0 and 11.5 were evaluated. Results show that increasing the compression ratio has little effect on NO\dx but increases unburned hydrocarbons emissions. Modest part load fuel consumption improvements were observed. Torque output at WOT (wide open throttle) increased, but did not reach the value obtained with gasoline fueling at the lower compression ratio tested.