Hi everyone I was reading an article on the web and it stated that premium gas only cars can run on regular gas. you'll just lose on perfomance. The knock sensor will handle everything else. Is this true can I get a conformation? Reason is of course everyone knows the price of Premium gas in CA is crazy $4.59 per gallon and climbing
these are 7-10 year old engines high compression and without the current days engines sensors.Read the manual about keeping speeds down and full throttle loads up hills,etc..
take your chances for people in denver or other high alt cities 89 will pass.Try it if you want the worst that can happen is a burnt piston or three
ohlord
knock sensors have come a long way in the last 7 years.
If you do a search you will find lots of threads on this topic and always tied to an increase in gas prices. What will you do at 6 bucks, mix in water? The sinple fact is that this is a high compression ULEV performance engine DESIGNED for premium fuel. Can you run regular in a funny car? NO! Knock sensors cannot compensate that much, period.
I've said it before and please don't take it personally, but you are applying a Ford mentality to a Mercedes and if you want to apply a Ford mentality then sell the benz and buy a Ford. The damage you do will end up costing you lots more than the couple bucks you'll save on a fillup.
But if you want to apply generic information then all I can say is take care and enjoy ruining the ride...
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just picking brains here! how does the lower octane gas effect our engines? is it the cats or can it damage the engine. i personally have always used premiem, but what is the possible damage?
pointing out a ny times article and they are not paying for your engine.
Mercedes did not scale this high compression engine to regular fuel.The engine management systems used now are quicker to respond to knock and detonation.
lower octane takes a lower level of compression before it ignites without the presence of a spark,just like a diesel.High compression engines develope much more compression of the air fuel mixture and require the extra delay of premium so the spark plug or plugs can ignite the mixture at the best time.
octane fuel to delay the firing until the stroke of the piston reaches the optimal point.Low octane will allow that to happen before the proper position in that cycle,slamming the piston down the bore when it is still trying to reach the arc of the crankshaft that it needs to be at to go on the down stroke,not a good thing.I will takes my chances with other forms of gambling
ohlord
That is an article written to the masses, and "the masses" DO NOT include MB owners (or Porsche, BMW, several others).
Most cars are designed to utilize premium fuel and those are okay on whatever pump octane you dump in. However, some cars are designed TO USE, not utilize, premium. In other words, the basic engine configuration REQUIRES a certain octane rating to perform nominally, not just optimally. The electronics that are hung on the engine don't "adapt" it to run on other octane and will do their best to compensate if you abuse the car by doing so, but they cannot rectify the underlying issue of the low octane because the static timing, combustion chamber and compression ratio are ALL geared towards the specified octane number. PERIOD.
So...running improper octane gas will save you about $3 on a tank of gas assuming an average fillup of 15 gallons, so $65 instead of $68 for example. If you fill up every week that saves you $156 a year, although you will fill up a bit more often because you won't get the same fuel economy. But I'll let you have the full $156 figure.
The cost of a pair of aftermarket cats welded in is about $300; OEM figure a grand a side. O2 sensors are $300-$800 a set depending on whether you buy universals and install them yourself. An EGR valve is a couple hours work and $140. Plugs aren't terribly expensive, but if you pay to change them they sure are. Cleaning up a combustion chamber could also be costly. All of these things are within the realm of possible damage by running improper octane fuel that as a result does not burn properly.
Is any of that worth $156 a year (which, coincidentally, won't even pay for your NYT subscription)?
So if you're going to dump regular gas in your engine, be sure to set aside the savings to pay for the added repairs you will incur (unless you first dump your car on some other unsuspecting soul). It likely won't pay for all of the repairs, so set aside some extra money for that, too.
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Well explained Ohlord I would not risk the engine with low octane gas. There were times I had to mix 89 octane with my remaining 93 octane in the tank. But just enough to drive to next station to fill proper octane.
I was filling up premium to my Volvo even when 20 cents price difference made 25%.
Driving often in the mountains I even used Premium in cars design for Regular. With premium struggling on steep slopes the car didn't have to downshift, giving not only much better performance but also fuel savings.
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