gas mileage vs. octane
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Member
Joined: Oct 2008
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From: Mt. Sinai, NY
2013 E350 wagon cuprite brown; sold:2014 ML63; R500 Saks Edition; R500; more W124s than I can count
gas mileage vs. octane
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?
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From: SF
Santa Cruz Blur
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?
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
Thread Starter
Member
Joined: Oct 2008
Posts: 141
Likes: 11
From: Mt. Sinai, NY
2013 E350 wagon cuprite brown; sold:2014 ML63; R500 Saks Edition; R500; more W124s than I can count
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.
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Joined: Feb 2010
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Mercedes R 320 CDI Sport 4Matic
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?
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Joined: Jan 2002
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From: Nashua, NH
2008 VW GTI
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.
