termite

Have owned the R500 for about 2500 miles and always put 91 octane in it because that is the highest grade at the local Hess stations. Just went on a long road trip from NY to VA and on the way south got a little over 17 mpg w/ an average speed of 65 mph w/ a large Thule pod on the roof on OEM roof bars. On the return trip [same ambient temp.] I used Sunoco 93 octane and got a surprising 19.5 mpg at the same average speed if not slightly higher...that comes to almost 50 extra miles per full tank. Has anyone else seen this improvement w/ higher octane?

sivajenny1

i have always used 93 octane from Sams Club or Costco and have got 18.5 to 19 mpg on long trips involving mostly highways. I have not tried 91 octane so wouldnt know the mpg for that.

sf280

a couple of factors.

How windy was it each day, that can make a big difference.

Is it more elevation gain going from NY to VA? Just wondering since on a recent trip from San Francisco to Tahoe, I averaged 18 mpg on the way out, on the way back I averaged 23.5 mpg - difference is SF is at 0 feet and Tahoe is at 6,000 plus feet

termite

Looking back on the weather conditions, wind doesn't seem to be a factor on a purely north to south trip and the return. similarly, pretty much sea level all of the way on the I95 corridor between NY and VA...funny thing is that now that i am home, the around town mileage is also a bit better.

memli

In Europe we have Shell V-Power 97 octane it runs much smother and better fuel consumption.

avlis

My other car requires 91 octane which I can only get at my local Sunoco station. Everywhere else is 93 octane or drop down to 89. I usually get 30mpg on a tank of 91. I missed my local station last time so I filled it with 93 Shell. I'm getting 35mpg on this 93 octane tank so far.