agstacker

I've always used premium but I'm wondering if its really necessary? Do you all put premium in your e class? Below is a link I was reading that had me thinking.

http://money.msn.com/saving-money/ar...a-b30bf27a090f

g2k

i have a E350 and with 268bhp i dont see why it would need 93 i used 93 for the 1st 1000 miles and i now use 87 and i now have 1900 miles the car runs exactly the same as the the first day....slow and still getting the the same gas mileage now if i had the E550 or E63 i would definitely use 93 but dont see why 268bhp engine needs 93 and if it does too bad because its getting 87 unless my engine starts to knock

Arrie

You say you used 93 octane fuel for the first 1000 miles and now use 87 octane and don't see any difference in fuel mileage.

I say either you are not telling the truth or the 93 octane fuel was NOT really 93 octane fuel but probably the same 87 that you now use and was just labeled as 93.

You will not get knocking as the engine is built to handle low octane fuel, you get poor performance and poor fuel mileage.

g2k

lol i knew this would be coming... yes im being turthful this isnt a high performance car lets be honest this car is under powered and i dont see why it needs 93 as for gas mileage its the same why would i come on here and lie about something like that and if it is lower its so small i cant tell

Dexion

go to a dyno, run a baseline test. Go fillup with 93 for a few tanks like 3 or so. Then run another dyno.

I know a few 268hp motors that benefit from 93 like Nissan's VQ35DE which I had in my Altima and it definitely did make a difference, especially noticeable was gas mileage however I had my fun with that car.

If your throttles never see more than sixty to seventy percent open then your absolutely right you won't tell the difference, also now it is winter so cylinder temps are lower so the chance for knocking is lower. As long as you stay off the throttle 87 octane is fine.

Arrie

You need to read my post again. It says if you are not trying to tell us a lie the 93 octane fuel was not 93 octane if you don't see difference in gas mileage compared to 87 octane you now use.

I tried myself on my E350 one tankfull of 87 octane fuel just as I did with the Audi Q7 I used to drive and the result on both cars was the same: about 15% worse gas mileage and very weak feeling engine compared to running on 93 octane fuel that I always use if available.

Engine power rating has absolutely nothing to do with the statement where you question the need of 93 octane fuel with only 268 hp engine. Engine can have only 50 hp output but if it was designed to run with 93 octane fuel it does it much better than with 87.

And, as you must know, octane rating does not change energy content of the gasoline. It only sets the compressibility of the fuel for preventing self detonation under pressure, thats all.

hanjaya1

Hi agstacker,
To Answer your questions, Yes it is necessary. Yes I put premium gasoline in my 2011 E-Class. Yes I agree with the link you provided.

The premium octane for the E-Class is not a recommendation but it is a requirement. Only in emergency situation, you can use lower octane but with some very descriptive precaution like fill partially and quickly fill up with premium gas ASAP, etc, it seems that you really want to use premium gas. I believe that the engine is designed for min 91 premium octane.

Please see the attachment below. The information I gathered comes from the operator's manual. The page may be different but it's in there.

You have to take min 91 octane. Therefore, I am using min 91 Octane for my E-Class. I will not buy higher octane than 91 (because it is not necessary) and I will not buy lower octane than 91 because it is not per the Fuel requirement.

It's your car and it's your choice. I follow the text book that come with this car.

g2k

look fellas.... im not here to say your wrong or right im just saying i use 87-89 sometimes and have not seen a difference in the way my car performs... thats my car..... and yes your right hp doesnt matter if the car was tuned to run on 93 then thats whaT YOU RUN in it.... but i really dont think the the w212 v6 was tuned to run on 93 or else it would knock(i believe) so once again im not here to say 87 wont give you less power or worst gas mileage but if i have to put it on a dyno to see the power difference then it not worth it to me ill just keep running the same gas that i have been running.Im not impressed at all the way this car runs i should have bought the 550,this car is nice for cruising and thats what i do with it ive had it since nov 9 2010 1900 miles on it and i love it, it just slow not what im use to and i dont see using 93 making it run any better im getting 22.5 mixed driving

g2k

i read it and its say no less then 91 so i guess ill start using 91 in the w212,i dont want to hurt the car ,thanks

Arrie

You are not getting 22.5 mpg in mixed driving if your mixed driving is what peoiple normally do.

Again, the fuel you have been buying as 93 octane is NOT 93 octane if it does not make any difference compared to 87.

I could argue that running 87 octane fuel brings 550 engine power output down so much that a 350 with 93 octane is not very far behind it.

g2k

you know what you are so right...... im not getting 22.5 right now could you be so kind and tell me what im getting because im reading my gauge wrong

pmb600

Oh god here we go again, another Premium fuel thread.

To the OP, don't take car advice from MSN Money. Mercedes engines are designed for Premium to get maximum performance and fuel economy and lowest emissions. Putting regular will force the engine to compensate for the lower quality and will subsequently reduce performance, decrease fuel economy and increase emissions. So there is no benefit to your wallet, your acceleration or the environment by putting in regular--stick with Premium.

Arrie

You fill up your tank all the way and reset your trip counter. Next time you fill up the same way and then calculate from trip meter and gallon amount what your actual mpg is. That is what you are getting.

Tjdehya

What are the long term effects of running 87? I hope that car is a lease, cuz I would hate for you come get on this website in a few years b!tching about how your $50k+ car quit the week after your warranty ran out.

Darn you Mercedes for building a car that wont last 4 years running on regular gas even though you recommend premium.

Any way I commend you for caring more about $.20 in gas difference rather than your $50k car.

golfster

I always run the highest octane I can find, but the highest I've seen in my area is 91.

FTB, you are near me, are there gas stations around here that sell 93?

Arrie

And using regular 87 octane is not saving anything in gas pricing as mpg goes down by about that same rate as what the price difference is. (Could actually end up costing more, not less.) The net result is very close the same cost for fuel but with low octane engine power is down and feels weak. Both my German made high octane engine cars do this and I guarantee g2k's car behaves just the same as all of them.

If there is no difference between 87 and 93 octane fuels in the car then the gasoline sold as 93 octane is not that.

ImInPA

Just my two cents: With today's variable valve timing and combustion electronics, the engines in almost all modern day gas engines can compensate for a fairly wide range of fuel qualities. If the owners manual states that a minimum fo 87 octane is required, there is no practicle benefit in using a higher grade of fuel. If the manufacturer states a minimum of 91 to achieve optimum performance, AND states something along the lines of "Using fuel of a lower octane level can result in serious damage", then by all means, use 91 octane or higher. If there is no accompanying warning, it is more of a recommendation than a requirement. Volvo used to "recommend" a min of 91 for their Turbocharged inline 6's. But, with no changes to the engine, somewhere around 2007 these same engines now only require 87 octane. There is a difference between a "Recommended min octane rating" and a "Required min octane rating." Also, keep in mind that octane in gasoline act to retard combustion and to allow higher compression ratios. IF you run 87 octane in the E350 and you are not experiencing pinging, knocking, etc., the you are fine using 87. Usually the symptoms of low octane only manifiest themselves when the engine is under load. As lower grade fuel actually burns more easily and completely, using the lowest octane that suits your vehicle is perfectly acceptable. Many years ago, I read an article about a group that went around and actually tested the octane levels of various grades of gasoline and found a fairly wide range of deviation between what was posted on the pump and what was actually going into your tank. Surprisingly, most of the deviations erred on the side of slight higher octane in the fuel than posted. The bottom line is that, if using the lower octane fuel is working for you, and you are not noticing any drivability issues, do what makes you feel happy. Of course you could do what I do and just buy diesel .

Tjdehya

Smoking cigarettes works for some people too. Some experience a decline in breathing performance, some don’t. Even though doctors recommend that you don’t smoke, it is not required. The bottom line is that, if using tobacco is working for you and you are not noticing any breathing issues, do what makes you feel happy. Of course you could do what I do and not die a horrible early death because of cancer.

And this is soooo not off topic.

Firestopper0383

I am firm believer to use what is required. If the car calls for 91 octane use it, it will only be beneficial in the long run. If the car calls for 87 octane then use it an be happy. But, if somebody is going to question or complain about a couple extra dollars having to be spent to fill up their $60,000 automobile, then maybe they should have purchased a different car.

ngerstman

There is no advantage to Mercedes to tell e350 owners to use premium gas if that didn't result in better performance, gas mileage and engine longevity. If it could run on 87 octane without any downside, wouldn't that be a marketing advantage versus other premium luxury sedans? Do you think Mercedes gets a kickback from the oil companies to help them sell more premium? Why would they tell you to use premium if it wasn't in some way required? Do what you like but don't delude yourself into thinking your not falling for the old "premium gas scam" or accepting the downside of using 87 octane. Party on . Ned.

g2k

not sure if this is directed at me but if it is ,no one ever said anything about $$ for 1.......2 if you had read the whole tread you would have seen a few lines above that hanjaya1 posted a post that the w212 requires 91 and i replyed " i read it and its say no less then 91 so i guess ill start using 91 in the w212,i dont want to hurt the car ,thanks " and 3....its not a lease its mine (if you must know) and ill will be getting rid of it in 2012 for the 2012 cls550 and yes ill be using 93 so you dont have to worry about me coming on here *****ing in 4years its really not that serious like i said before i got the car in nov 2010 and used 93 for the 1st 1000 miles and now have 1900 which means 2 maybe 3tanks of fuel under 91 so please come down thanks

g2k

no where in this tread is anyone complaining about $$$ so maybe you should read before you post

g2k

makes sence to me, a buddy of mine had a lincoln pick up truck that uses the same motor in it as the ford f150 at that time the lincoln said 93 but the f150 with the exact same motor said 87 not sure why when it was the same engine but he used 87 in both and they ran fine ,(no i do not know the long term effects because he didnt keep them for 4 or 5 years) so i can understand what you mean whan you talk about the volvo

g2k

ok ill try that,thank you

petee1997

MB has hundreds of engineers designing these cars to maximize their performance but there will always be someone who wants to reinvent the wheel. Seldom are they successful.
I use 91 octane because someone smarter than me told me to.