MB gasoline - regular vs premium

[Ducman]

I think it's widely accepted that a benefit of having a MERC is that it's often capable of running on low octane fuel and as a consequence it's more economical.

I know its a Tight A**ed way of going about it.
But i've met my fair share of self made people who drive expensive MERCs that run low octane fuel just because you can, and it saves more money day to day.
I wonder if it's pitched at the dealer level when they buy their first MERC and the Sales Consultant puts it forward as an economical virtue of the brand where applicable and whenever able.

After the customer is hooked on their virtuous MERC that runs on cheaper fuel.
It becomes a lifestyle choice and is extrapolated out to become a universal truth pertaining to MERCs.

In the OP's case and in respect of the subject matter of the thread.
Higher octane fuel is recommended, and there must be good reasons for it.

 

[skyactiv]

I'm going to add this little known fact since we are talking about octane.
GM stated last year they want 87 octane to be a thing of the past. I'm sure every other auto maker thinks the same thing.
The power density and emissions is the reason.
Sidenote: I remember back in the 90's when I was in high school tinkering with old V8's, you didn't build a V8 achieving
1 HP per cubic inch and running 87 octane. Now we have engines making more than 2 HP per cubic inch that run on 87 octane.
The auto makers are holding back "better" engines because Joe Schmo wants to put 87 octane in his 2.0L-320 HP Silverado of the future.

Not enough people buy premium and is the reason why it is more expensive than it should be.
GM knows Americans are dumb. When we have new MB owners that want to run 87 octane, no wonder auto makers such as GM want a new higher standard octane gasoline.

 

[RTexasF]

What does it say inside the fuel filler door? Premium required or premium recommended? Also, as stated previously, what does the owner's manual say about octane? Saving a few pennies just might cost you serious dollars.

 

[gizzsdad]

Originally Posted By: skyactiv
I'm going to add this little known fact since we are talking about octane.
GM stated last year they want 87 octane to be a thing of the past. I'm sure every other auto maker thinks the same thing.
The power density and emissions is the reason.
Sidenote: I remember back in the 90's when I was in high school tinkering with old V8's, you didn't build a V8 achieving
1 HP per cubic inch and running 87 octane. Now we have engines making more than 2 HP per cubic inch that run on 87 octane.
The auto makers are holding back "better" engines because Joe Schmo wants to put 87 octane in his 2.0L-320 HP Silverado of the future.

Not enough people buy premium and is the reason why it is more expensive than it should be.
GM knows Americans are dumb. When we have new MB owners that want to run 87 octane, no wonder auto makers such as GM want a new higher standard octane gasoline.

I'm going to add this little known fact since we are talking about octane.
GM stated last year they want 87 octane to be a thing of the past. I'm sure every other auto maker thinks the same thing.
The power density and emissions is the reason.
Sidenote: I remember back in the 90's when I was in high school tinkering with old V8's, you didn't build a V8 achieving
1 HP per cubic inch and running 87 octane. Now we have engines making more than 2 HP per cubic inch that run on 87 octane.
The auto makers are holding back "better" engines because Joe Schmo wants to put 87 octane in his 2.0L-320 HP Silverado of the future.

Not enough people buy premium and is the reason why it is more expensive than it should be.
GM knows Americans are dumb. When we have new MB owners that want to run 87 octane, no wonder auto makers such as GM want a new higher standard octane gasoline.


Very interesting, nice find!!

 

[Smokescreen]

You've got pay to play when it comes to running higher strung foreign cars. If you don't like it, get a Kia.


I'll keep my 2003 truck and continue to get older cars as needed. I don't need super high output and I can get better than EPA in anything I get behind the wheel of. 87 octane will do just fine. If I were to get a new commuter, I would go Skyactive and get the Mazda3...designed to get high mpgs with very high compression ratios using only 87 octane.

6L-366cubes = 330hp
3.8L-232cubes = 205hp
1.8-110cubes = 136hp

...suits me just fine.

 

[PeterPolyol]

Originally Posted By: skyactiv
I'm going to add this little known fact since we are talking about octane.
GM stated last year they want 87 octane to be a thing of the past. I'm sure every other auto maker thinks the same thing.
The power density and emissions is the reason.

Will be interesting to see if this ever pans out. With SPCCI, lower octane is better. According to preliminary dyno graphs of the Skyactiv X engine, low octane provides the most early HP (torque) and high octane results in more top end HP.

I may be ignorant here, but it seems like good ol' engineering might be a better idea than lobbying to change the entire fuel industry.

 

[Kestas]

Originally Posted By: skyactiv
Not enough people buy premium and is the reason why it is more expensive than it should be.

I've read where suppliers are gouging for the price of premium simply because they can. They write that people who need premium fuel are typically buyers of high-end cars who are affluent, and they care less than the average person for the extra cost of premium.

 

[MaximaGuy]

Thank you all for the informed comments and suggestions.
Yes, I will stick with 93 as that is what is required in fuel filler door.

 

[camrydriver111]

On my BMW I notice loss of power with regular. No pinging though. Knock sensor should prevent pinging.

I stick with whatever the manual says, and because I do notice a slight loss of power. Engine revs easily but needs to rev more to get the same level acceleration.

 

[camrydriver111]

Originally Posted By: PeterPolyol
Originally Posted By: skyactiv
I'm going to add this little known fact since we are talking about octane.
GM stated last year they want 87 octane to be a thing of the past. I'm sure every other auto maker thinks the same thing.
The power density and emissions is the reason.

Will be interesting to see if this ever pans out. With SPCCI, lower octane is better. According to preliminary dyno graphs of the Skyactiv X engine, low octane provides the most early HP (torque) and high octane results in more top end HP.

I may be ignorant here, but it seems like good ol' engineering might be a better idea than lobbying to change the entire fuel industry.


That's on the Skyactiv-X, isn't that the one without spark plugs?

If you look at the current skyactiv power is higher throughout the power bands.

 

[MCompact]

I use whatever fuel the manufacturer calls for.

 

[Kestas]

I find it troubling that automakers are lobbying to get rid of 87 octane fuel. The result would be they'll find it easier to meet CAFE standards and possible carbon emissions, but the driving public will be stuck with paying more per gallon, and more importantly, it'll cost more per mile of travel.

 

[vavavroom]

Originally Posted By: MaximaGuy
The MB from my signature calls for premium gas, was wondering why regular won't work.

Other owners chime in - other than premium results is less knock, anything out of the ordinary that regular fuel won't work.
As long as engine management is able to retard ignition there will be no detonation. However, fuel economy will suffer and engine power output will be reduced. That's why I use the recommended fuel grade.

 

[PeterPolyol]

Originally Posted By: camrydriver111

That's on the Skyactiv-X, isn't that the one without spark plugs?

If you look at the current skyactiv power is higher throughout the power bands.

Skyactiv X still has spark plugs and they're used all the time. Not sure what chart you're referring to, the X trumps both MZR and SA for power at all speeds according to image posted.

 

[bbhero]

Great, great post skyactiv. Spot on.

 

[edyvw]

Originally Posted By: MaximaGuy
Concur its not breaking my wallet.
BTW knock and retardation is under load or heavy acceleration and regular driving conditions one never knocks under normal loading.
Curious if the vehicle is designed to only take premium, my Lexus takes regular


Because MB is designed by people using autobahn everyday, while Lexus is designed by people riding train everyday.
Joking on a side (well, still staying behind statement about Lexus), ALL Euro cars require higher octane rating. Europe long time ago decided to use higher octane fuel due to higher compression ratio in their engines.

 

[camrydriver111]

Originally Posted By: PeterPolyol
Originally Posted By: camrydriver111

That's on the Skyactiv-X, isn't that the one without spark plugs?

If you look at the current skyactiv power is higher throughout the power bands.

Skyactiv X still has spark plugs and they're used all the time. Not sure what chart you're referring to, the X trumps both MZR and SA for power at all speeds according to image posted.


I'm comparing 91 and 95 for the current Skyactiv-G (just the grey dashed lines). Although there is no label on the Y scale so it's questionable whether to even take Mazda's chart seriously...

 

[PeterPolyol]

Originally Posted By: camrydriver111
Originally Posted By: PeterPolyol
Originally Posted By: camrydriver111

That's on the Skyactiv-X, isn't that the one without spark plugs?

If you look at the current skyactiv power is higher throughout the power bands.

Skyactiv X still has spark plugs and they're used all the time. Not sure what chart you're referring to, the X trumps both MZR and SA for power at all speeds according to image posted.


I'm comparing 91 and 95 for the current Skyactiv-G (just the grey dashed lines). Although there is no label on the Y scale so it's questionable whether to even take Mazda's chart seriously...


Oh yeah, the 20 on the Y axis represents a torque range in N m. The scale is the same for both graphs, so the visual curves are directly comparable. Yes, on 95RON the regular combustion engines including the Skyactiv clearly makes more torque on high octane.
The point was that SPCCI engines will not exactly follow that convention because both a higher cetane rating for the CI mode (of low octane gasoline), and a higher octane rating for high-compression SI mode can both be exploited for their benefits. 91RON chart shows a torque curve closer to that of a diesel engine without dropping like a rock up top, and the 95RON a flatter and higher curve for more specific output. And yes, now that gasoline is purposely being ignited by compression, that autoignition characteristic is measured via the "cetane" rating; the cetane rating of gasoline

 

[UG_Passat]

Originally Posted By: edyvw
Originally Posted By: MaximaGuy
Concur its not breaking my wallet.
BTW knock and retardation is under load or heavy acceleration and regular driving conditions one never knocks under normal loading.
Curious if the vehicle is designed to only take premium, my Lexus takes regular


Because MB is designed by people using autobahn everyday, while Lexus is designed by people riding train everyday.
Joking on a side (well, still staying behind statement about Lexus), ALL Euro cars require higher octane rating. Europe long time ago decided to use higher octane fuel due to higher compression ratio in their engines.


Europe octane rating is not the same as the US octane rating.

European 91 octane isn't the same as 91 octane in the US.

Due to Research Octane Number vs Anti-Knock Index.

But yes, the highest normal octane available in Europe is 98 RON, which is roughly equivalent to Sunoco 94, which is not available everywhere.

 

[slacktide_bitog]

worth posting this again

European vs US octane sales

type —— US -- European RON
—regular 87 -- 91 (this is not available in Europe)
premium 91 -- 95 usually the lowest grade available in Europe
premium 93 -- 98