cipstinger

Due to the rising cost of fuel my wife is concerned about buying premium fuel for her new GLK. I told her I dont care about the cost but it bothers her. Will regular or mid-grade fuel really harm the engine. keep in mind it is a lease.

thank you

Oldengineer

I've bought 3 Jaguars, and, now, a new GLK from my local dealer. I asked them this question, and, they indicated that if I damaged the engine using low octane gas, the warranty would not cover the repairs. When I owned the Jags - on several occasions, I got gas that I suspected was actually 87 octane. The cars ran hotter than normal, fuel economy was reduced, and performance was soggy. My other car, a 2010 Honda CRV, which is supposed to run on 87 octane, is also being fed 93, because it's fuel economy improved dramatically on trips using premium gas. I discovered that the 2010 Honda 4 cylinder engine is high compression, and, tried 93 in it to see if its engine management system would respond. The results I got convinced me to stick with 93 - the Honda's increased fuel economy easily offset the additional fuel cost.

Regards:
Oldengineer
2011 Mercedes GLK350 4Matic
2010 Honda CRV LX
1948 Chevrolet Fleetmaster 2 Dr. Town Sedan

kyoshiro

Fuel economy goes bad if you dont use recommended gas type. So you pay less but you get less mileage so its just worse for you in the end.
My friend's C300 gases up twice a week on Regular, I gas up once every 3~4 weeks, not that I have his actual numbers but he does more highway than me, I'm mostly city with around 400KM/Tank. At the end you only pay about 10 dollars more a tank for going Premium over regular with better mileage and better for the car so just tell your wife, its not gonna save money in the long run.

ohlord

is a lease you are responsible for damage not covered under warranty.
Read your owners manual the page about in an emergency and you need to fill with regular.
1/2 tank max.limit speeds.limit throttle on hills,fill rest of tank with preimum at first chance.Is that really how she wants to drive all the time?
If someone can't afford the extra 20 cents a gallon they should not buy nor lease an MB in the first place.What are we talking here 3 to 4 bucks a week

phil17

I can't believe people actually do this to save a couple bucks. Explains the financial crisis for me though. ppl getting cars they can't comfortably afford..

MBRedux

Forget all the above. Simple answer... No... nothing will happen, everything will be fine! I personally would use 89 (which is 94 RON) but even 87 (which is 92 RON) would be okay and still fall within the Mercedes 91-95 RON requirement. The onboard systems will automatically compensate. You may notice a little bit loss of power, and less overall mileage (due to the lower octane) but other than that, it will be fine.

PS: Go ahead.... DON'T BE AFRAID... and don't let everything on the net scare you. Half the time it's either half wrong or completely wrong. Rarely is it worth anything.

iewoals

It's really only about a $3 difference between regular and premium? And only $1.5 between mid-grade and premium for a full tank?

I'd say, just fill it up with premium. If you're intent on saving $$ I'm sure there are plenty of places to save more $$ at one time.

golfster

And blaming the temptation to use cheap gas on your wife...shameful.

sknight

All cars today from Mercedes and other manufacturers have maps designed for fuel variances. Even in Europe, the quality of fuel is variable. All engines, for safety, even have programs for less than 87 to avoid blowing the engine up. This has been the case since the 80's, even with Audis. Have a knock sensor, you then have cylinder by cylinder sensing and the program cam compensate.

Should you run lower? No. I concur that mileage losses will result. However, even in Europe, the cars can and are run regularly on our "super", which is mid grade. For performance, one can use as high as they can get in a high compression and/or forced induction engine.

Even with good fuel, some conditions within the engine can simulate preignition, as if lower octane were in there. If there wasn't either alternate maps, or adaptation for lower end fuel, NONE of these engines would last. On top of that, depending on how cold it is and your driving, you might even be able to get away with lower octane...

MBRedux

Everyone.... please.... in the US and Canada fuel ratings are AVERAGED.... yes averaged! If you look on the pump it says (R+M)/2 over the fuel rating. Look closer at the sticker and you'll also see the word "Minimum" as well. That word means that in most cases the fuel being disbursed from the pump is possibly higher than the posted average octane rating. Do you all know what all this means? Hmmmmm?

The octane ratings are an average of the RON (Research Octane Number) and MON (Motor Octane Number) rating systems for octane. (Essentially the European + American/2) So the number that you see on the pump is not the RON rating you see in your Mercedes Owners Manual or inside the filler cap door.



Without going into a huge explanation, the average rating is approx. 5-6 points lower on our pumps than the Mercedes Benz European RON requirement which in the case of the GLK is 91-95 RON... that means you can SAFELY use and STILL HONOR THE MERCEDES WARRANTY in the USA/Canada with pump ratings of 87-91(R+M)/2, which are the same as 92-96 Euro RON ratings respectively.

A Simple Chart / Mercedes Benz Octane Range for the GLK = 91-95 (RON)
USA/Canada 86(R+M/2) Octane Rated Fuels = 91 (RON) (That's if you can find it?)
USA/Canada 87(R+M/2) Octane Rated Fuels = 92 (RON)
USA/Canada 89(R+M/2) Octane Rated Fuels = 94 (RON)
USA/Canada 91(R+M/2) Octane Rated Fuels = 95 (RON)

Bottom line: ***So ALL FUELS sold in the USA or Canada with pump ratings of 86 or higher falls within the Mercedes requirement.***

Get it now? The original poster is fine using ANYTHING he or his wife wishes to use, and so could you.

Here's the best and simplest explanation I could find: http://en.wikipedia.org/wiki/Octane_rating

babyjocko

Lower octane will not damage the engine. It just provides lower performance and gas mileage.

So, the real question is, why did you get the GLK in the first place knowing that it asks for premium gas and you (or wife) are unwilling to comply?

About a week or two before you turn in the lease, be sure to fill with premium.

MBRedux

You're wrong!... and flatly! Look inside your filler cap door. It says, and I quote: ( 95 RON / 91 RON Minimum.) That's hardly "Premium" gas sir! I wish you would not use the term "comply" when you obviously don't know what the heck you're talking about!

In the USA and Canada, that's a pump rating of 86 (actually 87 because 86 isn't made) through 90 (actually 91 since 90 isn't made)!

91 RON = 87 US/Canada (R+M)/2
95 RON = 91 US/Canada (R+M)/2

87-91 is a very wide range from regular to semi-premium. Real premium fuels start at 98 RON ( that's 93-94 US/Canada (R+M)/2 ) for those that remember Citgo and Sunoco Super Octane fuels.

kyoshiro

The manufacturer claim for "unleaded gas" "premium gas" does get rather confusing for the general consumer, but yeah, in my mind, I put regular at 87 since thats the lowest, and 94 as premium cuz thats the highest. I dont settle for anything in between cuz I dont want ethanol in my GLK and I can has ethanol in my Mazda 4 banger lol.

On the side note, I think Hong Kong only imports 95RON fuel so the only difference when fueling up is additives most of the time, unless ofcourse you go to the real cheap ones which god knows what ratings they are lol.

However seriously, if you're concerned with fuel, why buy a car with such a large engine? Why not have settled with a 4banger and also a cheaper brand for that matter. Its quite funny how some people like to go 1/2 way with their purchases. (I wouldnt say investment cuz cars are liabilities)

MBRedux

To all those that do not know, currently ALL gasoline in the continental USA (and most of Canada) contains ethanol (year round) thanks to the powerful corn lobby of the mid western states, the Archer Daniels Midland Co. (ADM), former President Bush and the Republican Party for voting for the permanent change back in 2006. Now this same farmer friendly but car damaging lobby is heavily pressuring congress to up the percentage to E15 or 15% ethanol. Essentially, it's a "bail-out" "pay-off" subsidy to the corn growers to the tune of $1.3 Billion and has NOTHING to do with the environment or reducing pollution.

EPACT 2005 (enacted in 2006) created a Renewable Fuel Standard (RFS) which required that 7.5 billion gallons of renewable fuels be blended with gasoline by 2012. The RFS was expanded under the Energy Independence and Security Act of 2007 (“EISA”) to require that 36 billion gallons of renewable fuels be used in the nation’s motor fuel supply by 2022. EISA caps the use of conventional ethanol produced from corn starch at 15 billion gallons in 2015 and requires the remaining 21 billion gallons to be produced from advanced biofuels including at least 16 billion gallons from cellulosic feedstocks. By way of comparison, an estimated 10.6 billion gallons of ethanol were produced and used in 2009, up from 9.2 billion in 2008.

Bottom line, if you don't like ethanol enriched fuels, you better get use to it because congress just gave the green light to E15 on Feb 2011! Let's see what the Senate has to say.

PS: By the way, don't ask the guy sitting behind the desk or even the mechanics at the station, they don't know. If they say it doesn't contain ethanol, they're wrong. Most states require a sticker on the pump but it's not enforced very well.

phil17

in Ontario, most premium contains no ethanol actually. It's been marketed that way at least for Petro canada, Husky and Shell. The mid/lower grade has ethanol blended.

I also want to quickly apologize for my earlier post. I re-read it and it sounded very rude and uncalled for. Sorry about that folks. everyone can do as they please with their hard earned Money. With so much Propaganda and marketing campaigns its hard to know the truth anyways.. cheers

kyoshiro

I'm in the greatwhite :p so we have labels on the fuel with ethanol. Our shell 91 an chevron 94 do not contain ethanol. But yeah it's an inevitable future but at least there's still choice in Canada west coast atleast

MBRedux

Utter !!!!!!!!!

The fuel rating for the car is 91-95 RON. It says so right on the car. That's 87-91 (R+M)/2) for the USA and Canada which averages it's fuel octane rating by taking the Research Octane Number (RON), adds it to the Motor Octane Number (MON) and divides by 2.... hence the (R+M)/2.

I have $50K in my pocket for ANYONE willing to bet that this is wrong! Any takers?

F18BEN

+1 I agree with MBRedux 100%.. He is right on target.

ohlord

86mon which averages 91 minimum premium in the States.
A 10.7 cr engine will in the long term have issues running regular.
Look in your manual at the warnings,call your dealer and ask if you use low test will they honor the warranty if inspected and proven the failure was non minimum fuel grade rating.
And don't delude yourself the ECU stores knock sensor and timing data the dealer can and will pull it up to defend fuel related failures.
You call B.S. and pass out false information based on your lack of knowledge of Mercedes engines like Pez pushes candy out of a dispencer
You need an owners manual? page 335 336 337 or thereabouts if you can read and learn up


96ron+86mon=182/2=91 U.S. pump average premium minimum
Send the 50 bucks you are itching to give away Easy money my Dad used to say

What I always wonder is why Morons always raise the b.s. flag so proudly and when they get schooled fail to mail the check.
F18BEN he who agrees with the moron usually is one also, care to double up the check?


page 295 296 297 in the 2011 manual

thebishman

For God's sake everyone listen to MBRedux. The EPA states that every gasoline fueled vehicle sold in the USA has to run fine on regular unleaded, i.e. 87 octane. Whilst with using 91 or perhaps 89 you 'might' see a slight power increase; (doubtful that the driver would notice unless you're making multiple runs down the 1/4 mile), and perhaps a slight increase in economy, the car will run fine on 87 octane.

Now whether it will run for an extended period of time being forced a diet of E15 no one can tell regardless of what the idiots at the EPA have stated. All of the major manufacturers have loudly stated they can NOT guarantee the reliability of their gasoline fueled vehicles designed to safely run up to E10 now being forced to 'drink' E15. If you care about the long-term care of your GLK, or anything else btw, call your senator and tell them NOT to vote to allow E15 to potentially ruin our cars.

Bish

ohlord

listen to him just about as soon as listening to you.
Care to point out where the EPA mandates that a car has to run fine on 87?
You might want to tell that to Mercedes,Ferrari,Veyron ,BMW M3 etc.
You might want to also inform the EPA since their own advice is if a car has issues with 87 to raise it.That would be contrary to your unfounded statement that claims EPA demands all cars run fine on 87.
Where you come up with this crap is way beyond me,way ,way, way beyond.
Even the U.S. government fuel website lists Premium grade fuel for your model.
Stop being a tool and following blindly MBRedux. After all most of his technical advice is about as far off base as it gets.And at times if followed very costly.
Although I notice he is very adept at cutting and pasting info gleaned from the web and using it to bolster his lack of credibility.

Excuses to justify use of less than 91 minimum required by Mercedes on your 10.7cr engine are just excuses to cover being cheap.

Send all checks for $50 my way
They are piling up

MKenM

Now we all know that the farmers have a lot to gain from the increase in production of corn for the Petro Chemical industry (no problem with that). What you are all forgetting is that when corn is used for fuel to make us less dependent on foreign oil there is less corn to be used in food products. Look at almost any products on the grocers shelf and some corn derivative is part of the ingredients. So follow MBRedux's suggestion he is correct. Save money on gas now because some day soon you will spend more for food. For me, I like the performance and mileage I get on "High Test". So much for corn.

aggst1

I fill up the tank about twice per month. Let's say for each fill-up I buy 20 gallons of gas, and the cost difference between premium and regular gas is about $0.20 per gallon. So this conversation (and numerous others) is about risking damage to a $40- $50K premium car in order to save $4 per fillup (in my case $8 per month).

If this isn't the definition of being dangerously cheap, I don't know what is!

For some odd reason so many folks get so paranoid when gas prices go up and do stupid things. They have no problem spending $10 on junk food at the gas station, but an extra $4 to comply with specs is what upsets them... And my favorite: My neighbor will drive 15-20 miles every Saturday for a few pennies cheaper gas... He checks the websites to see who is cheapest.

ohlord

Send the 50 bucks my way, okay.
Save gas money to afford food? Now you are really pushing the cheap attitude.
Why not buy a cheaper little Hyundai that suits your frugality? That will surely allow you the spending money for the grocery store.

MBRedux

What horsesh*t! You have failed to convince anyone here, including yourself... There are no other explanations because there simply isn't, so please do everyone a favor and stop trying to fit a square peg into a round hole.

I stand by my comments 110%.

And please stop flattering yourself, there will be no forwarding checks.

PS: Look again. My bet was for $50K, that's $50,000.00 not some chump change $50 bucks! It appears you're not up on your roman numerals as well.