I am lucky I guess, last fill up at the pump it was $2.60 a gallon for the 92 octane... I am just gonna keep using it simply due to the rather low price here for premium.

 

Hey if it makes you and your truck happy, don't let me or anyone tell you it shouldn't.

But taking a quick look at Gasbuddy.com the Marathon at 802 S Main St, Leitchfield, KY (Top Tier certified too, and you can get Taco Bell and beer in the same place woo-hoo!) has 87 octane for $2.25/gal and 93 octane at $2.85/gal as of 1 day ago, and both are tied for the lowest in the 5-mi search radius for Grayson, KY. With a difference of $0.60/gal and assuming a 17 gal fillup* that's a difference of $10.20 per tank. If you figure just 1 fillup per week that's a difference of $530.40 per year, and it gets worse if you drive more than that. Even switching from premium to 89 midgrade would save $265.20 per year. Maybe it's just me, but that's money I would rather have in my pocket than Marathon's when it makes little to no difference.

*(supposedly from the manual these have a 19 gallon tank, but seems to starve out well before that lol so I seldom manage much more than 16 before I get anxiety)

 

Regarding the tank size: They might have 19 or 18 gallons total capacity but if you want your fuel pump to live as long as it can, you probably don't want to run it down to the point where there is less than 3 to 4 gallons in there.

For my 82 Prelude I use the high octane not so much for the octane rating but rather for it being the ethanol free gas so that its hoses that were not designed for ethanol don't dissolve.

 

Lowest octane i use is 95, because in Finland that is the lowest you can get, it has about 10 % ethanol in it, our premiun is 98 octane with max 5% ethanol in it. Previoys owner has used the blazer with more ethanol (re 85 gasoline) as an mix of 70% re85 / 30% 95 octane regular. The re85 has max of 85% ethanol in it.