Moronix

If you have a mustang with an Air/Fuel ratio indicator please post what your normal reading is here. Mine is bouncing between 13.9-14.2. I thought 14.7 was ideal.
Thanks

Siber Express

That is about what mine reads.

Moronix

Thanks for the info. I was wondering what is normal for this car.

JimC

Cruising mine is around that 13.9-14.2 as the computer makes adjustments. And 14.7 is lean but not unusual for idle or cruising - but the norm is that 13.9-14.2 range.

Wide open throttle of course that would be too lean - so at WOT you should see no more than 12 or so.

Siber Express

Mine goes down to 11.8 to 12.2 at WOT and coasting in gear will go to 20.0.

WindyMustang

Stock the AFR on mine is like a rock at 14 in a nice, steady cruise. Time will tell with the new tune!

Hellride

On the tracks apps for the '13 and '14 cars, Ford has adjusted the displayed a/f for stoich while running a 10% ethanol blend, which most gasoline is nowadays. For stoich at cruise and idle it should be around 1.39-14.2 while bouncing around a bit. At wot, I've observed anywhere from 11.8 to 12.3 in different parts of the rpm range. It's leaner than that below 2500rpms though.

To get an accurate display from some of these aftermarket gauges which may not have been calibrated for 10% ethanol...it won't be accurate.

Derf00

14.7 is ideal from a chemistry equation however in practice, there is a wider (much wider) range of acceptable ranges depending on environmental conditions, driving conditions, engine age, compression ratio, fuel type, ignition type/source etc, etc.

Here's a simplified version of real world application:

http://www.turbobygarrett.com/turbob...g_rich_vs_lean

mighted1987

mine bounce from 14 to 15.9 on cruising or no throttle at all, full throttle is between 10.5 to 12

J7erry

Good article Derf00. Now I know my 13.9-14.2 is normal. Been worrying about that since I put in my CAI. Thanks