Originally Posted by aaron.b
So you are saying 93 octane is giving you at least a 15% increase over 87? That's impressive but I have a hard time believing that would be the case long term.
E10 87 octane up here is 2.50 per gallon. At this price, and a 15% mpg increase, the 93 octane would need to be less than 40 extra cents per gallon for me to even try the 93.
I agree. On my recent trip there were too many uncontrolled variables (moderate to severe weather deltas within the trip) to get a good reading on 91 vs 87.
Isn't the EPA testing on the Focus non-STs done on 87 octane gasoline? I believe for the DCT those are 26mpg and 37mpg, city and highway respectively. While that doesn't
mean the 2.0 GDIs don't
get 10% - 15% better range with 91 octane, I would think Ford would be hammering "You get a whopping 37 mpg highway on 87 octane gasoline, but if you choose to use 91 octane gasoline you'll get a much improved 42 mpg highway."
If this is truly the case, Ford is dropping the marketing ball on a 160 SAE net hp car getting >= 40 mpg by simply failing to tell the customer to change the fuel octane.