Quote from: HD-Rugby on October 18, 2019, 08:31:23 AM
Ordering this setup for my wife's 2018 eco-boost Mustang... Thanks again. The SHO seems to run differently then before. There's always something to wipe up when I get a tank of fuel. Thankfully it's not on the intake valves. Does it matter what I run, regular or hit-test for a stock tune?
I would not worry unless there is unusual loud engine knocks especially in stock tune since the PI run regular fuel without a hitch. I would at least use 91 octane fuel to be on the safe side IMO!
If you're seeking better Mpg with a hint of performance add some Shell 93 octane fuel every other fill up for comparison!
I always like to use a top tier premium gasoline such as Shell or Chevron preferably @ a high turnover busy station. Z
Directly from owners manualYour vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87. The use of these fuels could result in engine damage that will not be covered by the vehicle warranty.
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.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.We recommend Top Tier detergent gasolines, where available to help minimize engine deposits and maintain optimal vehicle and engine performance. For additional information, refer to
www.toptiergas.com.
Note: Use of any fuel for which the vehicle was not designed can impair the emission control system, cause loss of vehicle performance, and cause damage to the engine which may not be covered by the vehicle Warranty.