I've been trying to avoid having having an argument on semantics with the peanut gallery (not talking about you) but for me it's all right there in print. The manual absolutely does not say it was designed to run on 87. It says it was designed to run on regular unleaded with a MINIMUM of 87 octane and that for best performance 91 or better is recommended. Simply put, Ford recommends 91 or better. If you're running 87, you're not running the fuel Ford recommends. There's really no debate here.
Here's the text:
"Your vehicle is designed to operate on
regular unleaded gasoline with a minimum
pump (R+M)/2 octane rating of 87 or
regular unleaded gasoline blended with a
maximum of 85% ethanol (E85).
Some fuel stations, particularly those in
high altitude areas, offer fuels posted as
regular unleaded gasoline with an octane
rating below 87. We do not recommend
these fuels.
For best overall vehicle and engine
performance, premium fuel with an octane
rating of 91 or higher is recommended. The
performance gained by using premium fuel
is most noticeable in hot weather as well
as other conditions, for example when
towing a trailer. See Towing (page 257)."
Btw guys, I have a Gen 1, so I have no dog on this fight. I'm also not an ecoboost fan. So y'all can all run 87 and handicap your trucks as far as I'm concerned. I personally think running 87 in a high psi turbo motor isn't a good idea, though. Running 87 may not void your warranty (unless it pings too much and you fail to bring it in for the dealer to look at) but it definitely wasn't designed to run its best on 87. It's all right there in the text. Plain as day.
Btw, the Gen 1 manual stated the actual amount of horsepower lost by running shit fuel. My guess would be you can thank the marketing department for pulling that same info from the Gen 2 manual.
by Truckzor
My reading skills are fine. Hows your comprehension skills. More crap being spouted