Will using higher octane (RON) fuel increases performance on W213?
Last edited by SufficingMocha; Sep 8, 2022 at 06:21 PM.




Basically, with electronic ignition there is no need nor is there any damage using something less than 95 RON.
Yes there is difference in performance: It is estimated that there is a reduction in horsepower of between 5% and 7% between using regular vs. premium: But keep in mind at 70 mph you are using between 40 and 70 hp to maintain speed. So whether you have 362 HP, as do in my E450 on premium, or 7% less, 336 hp, makes absolutely no difference. You are only using a small fraction of the horsepower available.
What does that 7% loss of HP translates to everyday driving: Nada, nothing. Unless you are drag racing or pulling a trailer you will never notice the loss of horsepower.
As to fuel economy: I have compared fuel economy, by dividing the number of actual miles driven by the gallons taken - not the mileage indicated in the computers in the cars, in my BMW 740i, BMW 740il, BMW 535, Porsche Boxster, Mercedes E350 (6 cylinder) and my E450.. I have yet to see any mileage difference.
There is always a horsepower race between Mercedes, BMW and Audi: so these manufacturers design their engines for maximum horsepower ratings and that requires premium gas.
By using regular the only real difference that you will see is in your pocket: Now unless you own stock in a major oil company, I prefer to keep the savings using regular in my pocket rather than paying extra for premium and giving it to the major oil companies.
Just my $.02
Basically, with electronic ignition there is no need nor is there any damage using something less than 95 RON.
Yes there is difference in performance: It is estimated that there is a reduction in horsepower of between 5% and 7% between using regular vs. premium: But keep in mind at 70 mph you are using between 40 and 70 hp to maintain speed. So whether you have 362 HP, as do in my E450 on premium, or 7% less, 336 hp, makes absolutely no difference. You are only using a small fraction of the horsepower available.
What does that 7% loss of HP translates to everyday driving: Nada, nothing. Unless you are drag racing or pulling a trailer you will never notice the loss of horsepower.
As to fuel economy: I have compared fuel economy, by dividing the number of actual miles driven by the gallons taken - not the mileage indicated in the computers in the cars, in my BMW 740i, BMW 740il, BMW 535, Porsche Boxster, Mercedes E350 (6 cylinder) and my E450.. I have yet to see any mileage difference.
There is always a horsepower race between Mercedes, BMW and Audi: so these manufacturers design their engines for maximum horsepower ratings and that requires premium gas.
By using regular the only real difference that you will see is in your pocket: Now unless you own stock in a major oil company, I prefer to keep the savings using regular in my pocket rather than paying extra for premium and giving it to the major oil companies.
Just my $.02
That E450 sounds sweet!








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Remember premium is "recommended" not mandated and by recommended Mercedes means for full performance: to be able to use all available horsepower.
In nearly 30,000 miles I have never floored my E450 from a stop sign and very rarely floor it while driving or passing. I drive "defensively", keep space between myself and the car in front of me and do not accelerate hard or drive agressively.
Before you ask, I choose the E450 over the E300 because of the smoothness and quiet of the 6 over the 4 in the E300. At highway speeds the E450 is quiet and smooth as silk a luxury car.
Remember premium is "recommended" not mandated and by recommended Mercedes means for full performance: to be able to use all available horsepower.
In nearly 30,000 miles I have never floored my E450 from a stop sign and very rarely floor it while driving or passing. I drive "defensively", keep space between myself and the car in front of me and do not accelerate hard or drive agressively.
Before you ask, I choose the E450 over the E300 because of the smoothness and quiet of the 6 over the 4 in the E300. At highway speeds the E450 is quiet and smooth as silk a luxury car.
From the owner’s manual, “ As a temporary measure, if the recommended fuel is not available, you may also refuel with unleaded regular gasoline with at least 87 AKI,”
In my opinion, high compression forced induction, direct injection engines requies the proper fuel. I use to say to people, don’t cheap out on the gas but that is not the case anymore with the high price of gas.




From the owner’s manual, “ As a temporary measure, if the recommended fuel is not available, you may also refuel with unleaded regular gasoline with at least 87 AKI,”
In my opinion, high compression forced induction, direct injection engines requies the proper fuel. I use to say to people, don’t cheap out on the gas but that is not the case anymore with the high price of gas.
Mercedes are sold world wide with great variance in the availability of fuel: therefore the engines and electronic ignition systems are designed and built to accommodate a wide range of fuels.
As to why Mercedes recommends premium fuel, see post #2 and #10 above: this is meet performance standards: 0-60 times and horsepower ratings.Nothing to with longevity or damage to the engine.
For example in Colorado the highest octane rating I have seen is 88. Mercedes and all other cars run just fine on 88 octane rating.
Last edited by JTK44; Sep 9, 2022 at 11:31 AM.
Mercedes are sold world wide with great variance in the availability of fuel: therefore the engines and electronic ignition systems are designed and built to accommodate a wide range of fuels.
As to why Mercedes recommends premium fuel, see post #2 and #10 above: this is meet performance standards: 0-60 times and horsepower ratings.Nothing to with longevity or damage to the engine.
For example in Colorado the highest octane rating I have seen is 88. Mercedes and all other cars run just fine on 88 octane rating.








Normal driving, without flooring it is not babying a car: Flooring the car from a stop light puts stress and wear and tear on the engine, suspension and transmission. It is a myth and wife's tale that your car needs to be run periodically at high rpm to "clean out the engine": Use the UPS driver for an example: they get rewarded for safe driving.
I am surprised that you do not know that regardless of octane rating the same and/or similar detergents are used by all major brands of gas. It is a myth and wife's tale that higher octane gas runs cleaner than regular. In fact regular, mid level and premium all provide the same amount of thermal energy.
see: https://www.google.com/search?q=whic...hrome&ie=UTF-8








Normal driving, without flooring it is not babying a car: Flooring the car from a stop light puts stress and wear and tear on the engine, suspension and transmission. It is a myth and wife's tale that your car needs to be run periodically at high rpm to "clean out the engine": Use the UPS driver for an example: they get rewarded for safe driving.
I am surprised that you do not know that regardless of octane rating the same and/or similar detergents are used by all major brands of gas. It is a myth and wife's tale that higher octane gas runs cleaner than regular. In fact regular, mid level and premium all provide the same amount of thermal energy.
see: https://www.google.com/search?q=whic...hrome&ie=UTF-8
Yes all gas of the same brand have the same detergents but that has nothing to do with octane or timing.




If you drive 15/20 minutes your engine will be at operating temperatures: 250 degrees F..
Last edited by The G Man; Sep 9, 2022 at 04:25 PM.


