What is the Best Fuel?

Time for a very unscientific experiment to determine which local fuel option will yield the best fuel mileage with my MX-5 Miata.

People often laugh when I talk about MPG’s and Miatas. Who cares? It’s a sports car, the fuel mileage is irrelevant… but after getting 36mpg on my recent 3,000 mile road trip, I’m quite impressed with fuel efficiency of my Mazda and would like to keep the MPG’s optimized as not all fuels are created equal.

What fuel I use is determined by what deal I could get on purchasing a fuel gift card on eBay. I’ve spend hundreds of dollars now buying discounted fuel gift cards and I think it’s the way to go. Most frequently I buy a $100 eBay Gift Card when they go on sale for $95 or $90 with 5% or 10% discount. Then I use that gift card to buy a $100 fuel gift card with 5%, 8%, 10% or 20% discount. Yes, there are that many discount options popping up on eBay now and again.

BP has been the most frequent card I’ve bought. Usually with around 10%-20% discount… so every gallon I put in the car I buy with a 10 to 20 percent discount, which combined with the BP rewards program yields a pretty good discount on brand name fuel. But like I mentioned earlier not all fuels are created equal… and I’m not entirely convinced that BP, despite being ranked Top Tier, is any better than Speedway for example, which isn’t Top Tier. So I’m going to run an experiment on a road trip using Speedway rather than BP.

Using my 1,000 mile Road Trip to Canada tomorrow, I’ll be able to run at least half of the trip on Speedway fuel. The method is simple, I run the tank down until it’s time to refuel, then I fill up and use the odometer (Trip meter) to divide the total mileage done by the number of gallons from the fill up. So for example if I do 300 miles on a trip and fill up 10 gallons, I get 30mpg  (300miles / 10gal = 30mpg).

With the last trip using BP fuel I got slightly less than that, 29mpg – which was pretty disappointing. I was hoping for something higher. Ironically after filling up at Citgo in rural Upstate New York near Watkins Glen I got a higher gas mileage than I did on New Jersey BP gas, 31.6mpg… which is significant, nearly 3mpg difference, or on a tank of 10 gallons that’s 30 miles more!

So lets see what happens with Speedway… if it yields better MPG’s I’m switching from BP and not looking back!

For those times when Speedway isn’t viable or available I’ve bought Sunoco and ExxonMobil gift cards, and on a recent trip to Palmer Motorsports Park to work with NER I was able to cash in my TIPs for a Shell gift card. So I’m prepared on all fronts, in US anyway. It will be interesting what kind of mileage I get on Canadian gas (which is significantly more expensive than US gas… like $10 per tank more).

The plan… I’ve just topped off at my nearby Speedway with nearly 10 gallons of Premium 93 octane. I will drive 250 miles to Cicero, New York where there’s a Speedway right off the Interstate 81, top off… then fill up again in Canada at Shell or Petro-Canada in Bowmanville which should last me for the duration of my trip there, and most of the way back to Cicero hopefully. Then the rest of the way home to New Jersey I’ll run Speedway gas again. So three tank-fulls will yield a good gauge of fuel mileage.