W204 / C200
- Thread starter Neil66
- Start date
grober
MB Master
Mercedes-Benz M271 engine - Wikipedia
there were various versions of these engines which were all forced induction [ kompressor or turbo]
compression ratios varied on these dependent on state of engine tune.
271.940 9.5/1
271.941 10.3/1
271.946 10.2/1
271.948 8.7/1
That said the engine management systems on these systems were sophisticated enough to alter ignition timing - "on the fly" from feedback from knock sensors etc. Factor in increased compression ratio from carbon deposits in the cylinder head V loss of compression from wear and its difficult to predict. Use what the manufacturer recommends. If its 95 octane then fine. You might want to try 98 to see if that improves running characteristics and /or mileage fractionally to offset any additional costs. So go by the manufacturers recommendation and then its a suck it and see situation. Only exception to that is if the engine has been modified to increase boost/power in which case you would probably want to run 98 octane.
there were various versions of these engines which were all forced induction [ kompressor or turbo]
compression ratios varied on these dependent on state of engine tune.
271.940 9.5/1
271.941 10.3/1
271.946 10.2/1
271.948 8.7/1
That said the engine management systems on these systems were sophisticated enough to alter ignition timing - "on the fly" from feedback from knock sensors etc. Factor in increased compression ratio from carbon deposits in the cylinder head V loss of compression from wear and its difficult to predict. Use what the manufacturer recommends. If its 95 octane then fine. You might want to try 98 to see if that improves running characteristics and /or mileage fractionally to offset any additional costs. So go by the manufacturers recommendation and then its a suck it and see situation. Only exception to that is if the engine has been modified to increase boost/power in which case you would probably want to run 98 octane.
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Use of higher octane fuel is sensible only if you are after the other benefits of the high octane fuel.... mainly the improved additives package.
Regular use of Shell V-Power or BP Ultimate won't make your car go any faster, but it will keep your engine clean and healthy.
So it's a maintenance issue rather than a perfomamce issue.
If you intend to keep the car for the longer run, then I would use either premium fuel, or regular fuel and then add Redex/Millers/Forte etc.
Regular use of Shell V-Power or BP Ultimate won't make your car go any faster, but it will keep your engine clean and healthy.
So it's a maintenance issue rather than a perfomamce issue.
If you intend to keep the car for the longer run, then I would use either premium fuel, or regular fuel and then add Redex/Millers/Forte etc.
