Originally Posted by latitud
I thought the HEMI required 89 or better? ......
Here's a copy/paste straight from the owners manual.
The 5.7L engine is designed to meet all
emissions regulations and provide satisfactory
fuel economy and performance when
using high quality unleaded gasoline having
an octane range of 87 to 89. The manufacturer
recommends the use of 89 octane
for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
While they recommend 89 Octane they allow 87. My choices here are 87, 91 & 93. Too hard to find 91 so I went with the 87 for awhile plus now that I'm back running the Diablo it has an 87 Octane tune - but I'm still going back to the 93 this weekend when I fill up. I believe that the 93 Diablo tune and gas makes for not only a better performing truck but a better running one as well.