SLK/R170: UK Shell optimax
Thread Starter
Newbie
Joined: Mar 2004
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UK Shell optimax
Guys,
I searched the archive for any discussion of this but couldn't find it.
I have an SLK 230K and generally use supermarket normal unleaded. What do other people use?? Has anyone else in UK found any advantage to optimax or is it just a waste of dosh??
Cheers,
Lonny.
I searched the archive for any discussion of this but couldn't find it.
I have an SLK 230K and generally use supermarket normal unleaded. What do other people use?? Has anyone else in UK found any advantage to optimax or is it just a waste of dosh??
Cheers,
Lonny.
Almost a Member!
Joined: Jul 2004
Posts: 36
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fuel?
I'm not from the UK so I will guess at some of your terminology.
I believe you are talking about fuel. I always use a 92 octane premium fuel. I find that my SLK runs smoother on it and it is worth the extra 15 to 20 cents per gallon. A premium fuel from the supermarket stations is probably just as good as purchasing your fuel from a name brand station and may save you 10 or more cents per gallon.
I believe you are talking about fuel. I always use a 92 octane premium fuel. I find that my SLK runs smoother on it and it is worth the extra 15 to 20 cents per gallon. A premium fuel from the supermarket stations is probably just as good as purchasing your fuel from a name brand station and may save you 10 or more cents per gallon.
Almost a Member!
Joined: Aug 2004
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From: ireland
austin-healy sprite,slk black
hi
i am just across the pond in ireland, i use it sometimes and feel i get better fuel millage [33-35] with the shell. true story my wifes car failied the mot test on emmisions, idle, i rang the dealer and he told me fill it with shell .i thought he was mad but had nothing to loose. result passed the retest
all the best
fab
i am just across the pond in ireland, i use it sometimes and feel i get better fuel millage [33-35] with the shell. true story my wifes car failied the mot test on emmisions, idle, i rang the dealer and he told me fill it with shell .i thought he was mad but had nothing to loose. result passed the retest
all the best
fab
Newbie
Joined: Oct 2004
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Shell optimax is 98 octane fuel, the SLK (320 anyways) only needs 95 octane to perform to its fullest. Only highly tuned engines like ferraris actually need 98 octane fuel. Using it in a car which doesn't require it can actually reduce power output. Because the SLK engine isn't heavily tuned, 95 is fine, and in emergencies; even 91 is okay (as long as you don't push it). Check the manual for what octane rating to use for a 230K, it will tell you in there under "At the filling station"
Newbie
Joined: May 2004
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From: San Diego, CA
2004 SLK32
We don't all define the pump octane number the same way. In the UK they use RON, that's why we see "high" octane ratings being discussed. In NA, we use (RON + MON)/2. The 95 RON in the UK is about the same as our 91. There is a slight drawback to using only RON. Since RON is determined under a light load, the fuel may behave like a lower octane under heavier (more realistic) loads. So, it is possible for a RON of 95 to behave like an (R+M)/2 fuel that is less than 91 under real driving conditions (maybe more extreme weather). This may be why we hear some people in regions using RON claiming they see better performance with 98.
