I fueled up my car for the first time used 93 octane. A couple days later I was going through manual for something else and came across recommended fuel of 87 octane. I thought they would recommend a higher octane.. Would 93 burn too hot for newer motors causing damage? I'm not opposed to using 87 since it's cheaper..

 

That's pretty strange, they must be pulling a lot of timing to run 87 octane in an 11 to 1 car. 93 just burns slower so the computer can advance the timing more. I would run 93 especially when it's hot out

 

I've been running 87 in my car since day 1. It looses 8hp on 87 octane vs 91. The only time I run 93 is when I'm doing a track day.

 

Yeah I'll be running 87 going forward..

 

The articles I have read say the difference in power between 87 and 93 is only 4 HP.

Modern high swirl cylinder heads with variable valve timing allows for very high compression ratios. The 2 liter in the Focus is 12.x:1 and it recommends 87 too.

 

The idea that using Premium could hurt your engine is patently ridiculous.

 

Ford says on their website that GT power ratings were achieved using 93 octane gas. If memory serves, since day one, the Coyote has been 'premium recommended' (not the only car to do this, the base Corvette has been the same way since the C5 debuted).

 

How could 91/93 gas damage the Coyote?
In my 2012 Focus (2.0L) my manual states that 87 is okay but more performance can be had with higher octane fuel.

 

Octane is not what most people think it is. If you want to know about it,you'll have to do some reading online. I read a lot some time ago and came away with a completely different perspective and some confusion.
No,it will not burn hotter.It will allow for more squeeze b/4 igniting . I use 93 only and usually alcohol free.