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Evening all.


I came across an article that stated that the ethanol additive in most gas is actually bad for your engine. It attracts water and can lead to o-rings wearing out and other engine problems. Many of the posters who I've read responses to always use ethanol free gas. Going so far to use the puregas app(or puregas.com locally) when they travel to find ethanol free stations.



I have a 2006 SLK55 AMG with approx. 73,000 miles. I've been told that AMG engines can last to 250,000 miles but I was looking around locally and was surprised to find stations that sell ethanol free gas, usually at 90 octane. Some at 87 octane, But none at 91 or 93 octane.


I'm curious how you all feel about the subject. Do you try to use ethanol free gas? Are SLK's engines attuned to perform better with 10% ethanol? Would 90 octane ethanol free be considered "premium gas" that MB wants us to use?



I'm seriously considering using Sunoco or Wawa gas at 90 octane ethanol free if it will help my engine last longer. Even the Valero near me sells 90 octane ethanol free gas.



Thoughts? Thanks.
 

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Little option in the UK, mine is just coming up to 70K.

Possibly, it may be an issue if the car stands for long periods.
I use mine pretty much daily.
 

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If you go for the higher octane stuff in the UK such as the Shell V-Power that has less (none?) ethanol in it.


Personally I'd not bother unless you had definitive proof it was going to cause an issue - which it shouldn't with a modern car like an SLK, although in the UK I believe they are now upping the percentage of ethanol - not sure when this comes into force.



The only time I have ever had it cause an issue was with my previous MV Agusta F4 motorbike - I noticed that the tank was ever so slightly starting to distort, something you'd only notice if you were looking very closely. A look online confirmed that it was a real problem in the US where they use more ethanol, so I switched to V Power/BP Ultimate and it got no worse, but US owners were needing new tanks it was so bad. I then sold it and bought a Yamaha.
 

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If you go for the higher octane stuff in the UK such as the Shell V-Power that has less (none?) ethanol in it.


Personally I'd not bother unless you had definitive proof it was going to cause an issue - which it shouldn't with a modern car like an SLK, although in the UK I believe they are now upping the percentage of ethanol - not sure when this comes into force.



The only time I have ever had it cause an issue was with my previous MV Agusta F4 motorbike - I noticed that the tank was ever so slightly starting to distort, something you'd only notice if you were looking very closely. A look online confirmed that it was a real problem in the US where they use more ethanol, so I switched to V Power/BP Ultimate and it got no worse, but US owners were needing new tanks it was so bad. I then sold it and bought a Yamaha.
I think you can assume all UK fuel contains 5% ethanol.

https://support.shell.com/hc/en-gb/articles/115005935369-What-is-Ethanol-
 

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The ethanol bashing articles were put out by the oil companies when Ethanol was first coming out. Ethanol is actually very good. It has more knock retardation than petro even at the same octane and it absorbs water, but it used to accumulate in your gas tank anyone. Now it is absorbed and burned. And no, it will have no adverse affects on your engine. 100% ethanol does, but even E85 does not. If you have seen a curve of how corrosive it is you would understand. There are cars from the 90's running E85 on stock fuel systems with no issues and have for well over a decade with no ill effects. Run the ethanol and be happy :D
 

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Discussion Starter #7
Thanks guys. Much appreciated.


Is it safe to assume that Exxon/Mobil 93 octane is very similar or equal to Shell V Power 93 octane in engine protection etc.?
 

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Thanks guys. Much appreciated.


Is it safe to assume that Exxon/Mobil 93 octane is very similar or equal to Shell V Power 93 octane in engine protection etc.?
Both are top tier. If they offer 91 you can use that also, more octane is not better when it is not needed.
 

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90? in an v8?
your owner's manual does not say use 90 does it?
I have used Shell 93 for over 11 years in my SUPERCHARGED :D 55
I have 112000 miles. I am not worried about it
No stations (except Mobil but they are few and far between) that I know of have 93 in Canada. Best we get here is 91.

The ethanol bashing articles were put out by the oil companies when Ethanol was first coming out. Ethanol is actually very good. It has more knock retardation than petro even at the same octane and it absorbs water, but it used to accumulate in your gas tank anyone. Now it is absorbed and burned. And no, it will have no adverse affects on your engine. 100% ethanol does, but even E85 does not. If you have seen a curve of how corrosive it is you would understand. There are cars from the 90's running E85 on stock fuel systems with no issues and have for well over a decade with no ill effects. Run the ethanol and be happy :D
Thanks guys. Much appreciated.

Is it safe to assume that Exxon/Mobil 93 octane is very similar or equal to Shell V Power 93 octane in engine protection etc.?
Mobil 93 has ethanol, Shell 93 does not.

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There are as many yes it harms/no it does not harm opinions as there are stars in the universe.

Here are but 2:

https://axleaddict.com/misc/Pros-and-Cons-of-Ethanol-in-Gas

https://www.digitaltrends.com/cars/the-truth-about-ethanol-in-your-gas/

Opinions are like well, you know, everyone has one :wink: . Our Shell 91 is about $1 more a gallon than say Ultramar (who until recently sold ethanol-free 91 but now does not). They can charge the same price but get gas cheaper wholesale because ethanol is cheaper than gas.

There is an additive you can buy that purportedly eliminates ethanol in gas. But at $15 a jug, might as well put in Shell 91 and save the aggravation.

Me? I'm not completely sold as to ethanol being ok to use. Short term? Who cares. Long term, well I just don't know. I'm not a mechanic, just an ordinary schmo who has an opinion lol
 

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Shell V-Power ranges from 91 to 93 octane both with and without added ethanol. It just varies from station to station, and it's up to the station owner whether or not to sell pure gas.
 

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I have not had any problems with modern fuel injected vehicles, using petrol with ethanol. But have had loads of problems with my older motorcycles with ethanol in petrol. It does absorb water if you leave it for a long period, so using your car every month or so after filling with fresh fuel is a good idea. i have phoned the fuel company technical departments for shell, esso, and bp here in the uk and the only one that doesn't use ethanol is esso supreme plus unleaded, so that's what i use. You could phone the fuel companies where you live to find out if there are any near you that provide ethanol free petrol. I use esso supreme plus unleaded in all my vehicles, and i'm lucky to have a gas station just around the corner that supplies this.
 
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