Fuel matters a lot. If you don't put fuel in, it won't go.

 

Guess it wasn't in the title, but OP asked after the V8 - TT stuff will nearly always benefit from better fuel.

Shame the owners manual and compression seem to indicate the older 5.0 won't really gain from more than 87 octane.

 

I look at it this way. If you want performance, don't skimp on fuel grade and pay up. If you want to save money at the pump, then get a GM pick up with the 5.3 V8 and run 87 octane on it all day, everyday. It will happily drink that without a complaint and get 20+ mpg. The 4.3 Ecotec V6 does even better and will happily run on 87.

 

Look at GMs 6.2 as well, needs premium. Slightly less compression than us, sure you can run 87. But the engine sure doesn't like it and same issues as running 3rd Gen Coyote on 87. Turns the 6.2 into lazy mode and ping pong ding pong knock.

 

Whatever you do, try to use top tier fuel. Really does make a difference and I was surprised that stations you'd normally think of as discount fuel like QT and Costco are top tier.
https://www.consumerreports.org/car-...h-extra-price/

Gas Test Findings

For its test, the lab operated an engine continuously for 100 hours on a cycle to represent 4,000 real-miles of use. The engine was then disassembled, photographed, and its key components weighed and measured to determine the thickness of carbon deposits. Six fuels were used, randomly selected and split among three basic gasoline sources and three Top Tier.

The results showed that on average, Top Tier gasoline had 19 times fewer carbon deposits on injectors, intake valves, and in the combustion chamber when compared to regular gasoline.

AAA also found Top Tier gasoline can have a cleansing effect, reducing intake valve deposits by 45 to 72 percent when used over a 5,000-mile interval. Variation in the results is attributed to the detergents used by different brands.

Further, analyzing gas prices over a 12-month period found just a three cent price difference between non-Top Tier and Top Tier gasoline.
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93 octane only. These 2018+ 5.0s love it. Its amazing Ford can get them to run on 87.

 

87 works just fine.

 

You actually want to kill your fuel economy??

 

Holy necropost, Batman!

 

It runs rather nice in the 5.0, yeah I get a couple MPG less, but for a dollar less than regular fuel? Yeah I'll take it!