[GuardianFlash]

Hi, I know people say use premium gas. I have been using 89(mid-grade). Gas is very expensive here in Vancouver BC Canada. I have nothing to worry about right? Cost me $65+ to fill the tank with 89. 91 would be insane.

 

[stewartw]

I filled up st shell the other day, paid £69 for 50l at £1.38 pence per litre.

UK£ 69 = 110.453191 Canadian dollars

This was for regular diesel, Vpower diesel was £1.47 pence per litre

 

[Mike Tee]

The engine needs 95 RON. 89 Pump Octane is about the same as 94 RON. So it's very close, could be OK. 91 Pump is about 96 RON...could mix it 50-50 to be sure you're meeting the minimum standard. The compression ratio is really high.

 

[Canada Stig]

Mine runs fine on either. Actually I notice it runs better on 91 in the summer and better on 89 in the winter. Must be the additives in the blends.

There are many owners who have used 89 in these cars for years with no issues. The automaker will not list the "real" minimum octane for the engine anyway, as they cannot control fuel quality. Fuel wholesalers in Ontario typically sell one grade of gas - regular - and pills to add to the tanks in order to make it 89 or 91 (or 94)..so 91 may be 90, or 92, or whatever depending on how full the tank was, how many octane pills were added, etc. Same with the mid grade (and some retailers - such as Ultramar - sell 90 as their mid grade, not 89). The only consistent product would in fact be the 87.

When I get a service loaner it runs like crap and it is pretty obvious people put regular (87) gas in it before returning it. Best to avoid that.

 

[guenter]

Mine runs fine on either. Actually I notice it runs better on 91 in the summer and better on 89 in the winter. Must be the additives in the blends.

Makes sense, the 89 has ethanol and although it's detrimental to milage, it's likely to make the engine happier in winter

I've used all, in particular kept my ear open for pinging with the 87 grade .... nada

 

[jaysoulz]

Is there any issue if we use the Octane 87? I switch from Octane 89 to 87 and it has been a month and I don't see any problem. Is there anything I need to pay attention for using Octane 87? Thx

 

[RedMercedesGuy]

In my area we have 87, 89 & 93. My C230 manual recommends 91 so I've been using 93. My former car, Altima 3.5 SE recommended 89 ocatane and I tried running a few tanks of 87 through it. Ended up with an O2 sensor failure and rough running. Switched back to 89 after replacing the O2 and I had no further problems.

IMO, if you're going to spend the extra money to buy a higher performance car that requires higher octane fuel then spending another $.10 per gallon should not be a big problem and could forestall big problems later on.

 

[jaysoulz]

In my area we have 87, 89 & 93. My C230 manual recommends 91 so I've been using 93. My former car, Altima 3.5 SE recommended 89 ocatane and I tried running a few tanks of 87 through it. Ended up with an O2 sensor failure and rough running. Switched back to 89 after replacing the O2 and I had no further problems.

IMO, if you're going to spend the extra money to buy a higher performance car that requires higher octane fuel then spending another $.10 per gallon should not be a big problem and could forestall big problems later on.

Sound fair. But did anyone got major problem by using Octane 87 all the way? Is there any expert in these stuff that can give me a good answer?

I only use my car like twice everyweek for few hours running, but even that, cost me like 200-300$ /mois for refilling as it cost me 80$ to full up with Octane 87. With Octane 89/91, it will be about 90-110$.

In long term (let say 5 years), if you use Octane 87 versus mix of Octane 89/91, you will save lot with the fuel price that keep increasing. If the problem is not big, then why not use the Octane 87 instead? Talking about the price of fuel versus price of repair if we use normal quality fuel versus mix medium/premium.

 

[DEVOURS]

Sound fair. But did anyone got major problem by using Octane 87 all the way? Is there any expert in these stuff that can give me a good answer?

In long term (let say 5 years), if you use Octane 87 versus mix of Octane 89/91, you will save lot .....

This is an old subject.....The expert is "gregs210". Search for many more premium fuel posts in Benzworld and see what they say also.........

You could ask this question in the "General Forum" way above the B Class forum too. ....Or you could closely follow the B Class car manual. :read:

I've only used Premium fuel in mine,... and all if fine for me.

 

[rtron2005]

High compression engines or as in BMW and Mercedes , finely tuned engines need the higher octane to not ping or cause detonation, I am not an expert at this by any means. but, have heard of someone scrapping a bmw running it on regular..what went wrong in the motor I couldn't say , I don't know
I know I did see honda advertise one of their cars once,they stated that it had x amount of horsepower when premium gas is used and x amount of mpg when premium was used.
They did not say "don't use regular" just that you would get optimum performance with hightest as we used to call it.

I will always use hightest in my b-200 or any car in which the manufacturer requires it. There is usually a reason they require it.
I also hear that using hightest in a car requiring regular gas is a waste of money.

Guess the best place to find out what low quality gas will do to your engine would be a drag racing ,engine building site or forum .
as for me I'm not going to gamble..
And yes I hate paying the high gas prices, lucky were not in Europe as our friend pointed out $110 to fill up with regular diesel and more with v-power diesel...I did not know there were two grades of diesel..anything to make a buck , these oil companies...even here the diesel is more expensive than gas..which is a sin..as more refining is required to manufacture gas than diesel so diesel should be cheaper than gas as it was before the demand went up.

LOL... sorry for the rambling ...lol gas prices....thats the real problem
But , please don't ruin your car with cheap gas, you won't save in the long run!

 

[rtron2005]

The engine needs 95 RON. 89 Pump Octane is about the same as 94 RON. So it's very close, could be OK. 91 Pump is about 96 RON...could mix it 50-50 to be sure you're meeting the minimum standard. The compression ratio is really high.

Mike, w.t.h you talking about I'm RON don't tell me they are measuring RON's

 

[Mike Tee]

Research Octane Number = RON
Motor Octane Number = MON

The engine requires 95 RON

RON is always about 10 points higher than MON

North American Octane ratings are an average of RON and MON - if you read on the pumps it should say "Pump Octane: RON+MON/2" or similar.

So the point being made in the above post by me is that our 89 Octane fuel in N. America is about 5 points higher on the RON scale, meaning about 94 RON. The car needs 95, so our "89" is very close to meeting the car's minimum standards.

 

[rtron2005]

I thought I read somewhere the b-200 required 91 octane now I did not notice if that was mon or ron
So, I try to keep it simple and but in the hightest, in the states now it is 94 for premium.
I believe in Canada its 91
Lots of people don't buy cars with premium requirements because of the extra expense.

 

[pfsantos]

Ron (not RON, lol) - ya read the same thing. 91 puts you at 96 RON, so that's what I use.

I like to push the engine frequently and don't want to worry.

Mike's explanation was only missing that the forumula of averaging the RON and MON is called the AKI (anti-knock index). It's silly that they can't just put RON on the pump like in Europe.

Kinda on topic...i've heard some people who don't know better say that the engines in Europe are better cuz they use higher octane...they don't realize they're comparing different ratings.