New record set this am. 387. 12.4 gallons to fill. This is the first full tank with my new tires though. I wonder if the slight difference in size is throwing my mileage out. It was only supposed to be .06% difference in diameter.
Best I've had so far is 557 on a tank; averaging around 500. Shell 91 V-Power. I've noticed consistently lower numbers with Sunoco Ultra 94 (ie 475/tank).
I got 433 miles on one tank on my Speed 6. No I'm not lying either. Took just over 14 gallons and I averaged just over 30mpg. I bet if I had cruise at 55 I'd have gone even more miles.
I'm being DEAD serious and truthful here, but there's an important detail. This was in beginning of August on my trip to Florida. I manipulated a tank of gas as an experiment through the Carolinas. I set cruise on 65mph, and NEVER touched it. No hills or anything, no braking. PURE STRAIGHTAWAY, so this isn't exactly accurate and real world, but nonetheless I did go 433 miles. hehe
Pulled over once at a rest stop. My next tank I put it cruise at 75, and my MPG dropped by 3mpg. I guess that's why the Speed limit used to be 55. It truly does save gas, but let me tell you. NEVER AGAIN WILL I DO THAT. It was bordering UNBEARABLE. However, I was in no rush so I said WHY NOT. hehe I could have pushed for 450, but I was below 1/4 tank so I filled up. True story.