SmittyAMG

So, just confirmed, while the gas door says 98 RON, it does say in the manual 91 Octane. I have a 2009 that was sold in SO Cal.

Odd.

SmittyAMG

To the OP, if any of these stations are close (http://pure-gas.org/index.jsp?stateprov=CA), you could try and see if the sound you hear goes away. If so, likely ping. If not, not ping.

looney100

If you're planning to keep your car for a while and care about performance, spending the money on top tier gas is well worth it.

Most gas stations in large markets operated by the majors sell many millions of litres per year, fuel going stale is not a concern. Most tanks hold only a few days worth of sales.

jmueller

Your symptoms, at least to me, seem like you are getting gas with very high contents of ethanol. Does your car smell like it's running rich after you get it to operating temps and then park / turn it off? Does the car idle rough (more than normal) on the days when the you hear or feel the pinging? If your answer is yes to those, those are generally signs of high ethanol content fuels. Our cars do not run well on ethanol-rich gas.

whoover

Not lobbying or anything, but I've kept all those cars for a long time. Eight years of hard driving is about average. I always buy the full extended warranty when I buy a car because I do keep them. And I've never had an engine problem that could be attributed to deposits.

Of course, driving style is important in preventing deposits too.

m a x i m u s

by the by, I just took the porsche out and on a lark unrolled the windows. I heard a few pings.

nkc

i use stp octane booster, have used for 2years now, no issues no cel...... our fuel here maybe ron 80 if there is anything like that, i think we get the lowest 87, so stp is a must and it helps reduce the pings and gives the much needed power.

i am on v4 eurocharged tune 93 and de-catted straights, with weistec air filters and row airboxes

my friends in porsche panarema n lambos also use the stp no one has complained yet, my uncle in dallas was also advised by the mb dealer to use stp in the states too..... so i guess it doesnt harm that much........

nkc

infact as i speak, i have 6cartons of stp under my step, can post pix, if it helps clear ur doubts

RawBenz

Octane Booster IMO does not damage your engine, it can foul your plugs but that's very rare. Especially on our cars, it's highly unlikely. I use octane booster every second fill up.

When i'm going to use it, i like to drain my tank to empty and then fill it with booster then fill a full tank. Keeps things clean IMO. Just in case i get a crap batch of fuel.

nkc

am even hunting for lucas, but cant get international shipping

Dr Matt

Most octane boosters are a joke. Read the label and you will see a can often raises octane by "one point". That is not 91 to 92, it is 91 to 91.1. Waste of money IMO. If you really want to raise your octane, add Torco or Tolulene.

I can only get 90 at the pump here so I run a can of Torco in every tank of my CL65 with my E/C 93 octane tune. Used to run it all summer in my Lightning too. Both making over 20#'s of boost on 90 octane fuel. My L ran 11.2's at full weight on 90 octane and Torco. CL ran 11.04 Monday on 90 octane and Torco. Yes it will leave deposits on your plugs, but a few tanks without Torco and they are gone. Never had a part fail due to it and I have burned over 30 gallons of Torco.

Clark Kent

Agreed. These 6-8 oz bottles of 'octane booster' can't possibly make a difference. How can 8 oz of anything really affect 19 GALLONS of gasoline?

I have used Torco at the track (road course) and it seemed to have a mild effect on performance. It comes in a 22 oz container and it is recommended to use the full container per tank. I don't use it often as a street driving 'booster' as it costs $28.

I tend to go to the track almost once a month so I run it through a tankful all at once on that day. So far I do not see any negative effects on my engine during daily driving.

Diabolis

From a page on nwcc.edu:

Gasolines are most commonly rated based on their Antiknock Index (AKI), a measure of octane quality. The AKI is a measure of a fuel's ability to resist engine knock (ping). The AKI of a motor fuel is the average of the research octane number and the motor octane number (R+M)/2. This is also the number displayed on the octane decal posted on a gasoline pump. In general, a low research octane could cause a low to medium speed knock and run-on or dieseling after the engine is shut off. A low motor octane could cause engine knock when power is needed during acceleration such as passing or climbing hills. A typical average octane number of 87 would contain a research octane of 92 and a motor octane of 82. However, it could also be the average of 94 and 80 depending on the availability of blending products on hand at the refinery. These different blends can affect engines differently, depending on the octane requirement of that particular engine, and explains why engines can perform differently with a change of fuel.

The first thing to try - as others have suggested - is a different blend of gas, even if it's of the same octane rating as what you currently use.

Assuming that you really are experiencing pinging (and not some other random noise that sounds like it), it can be caused by anything from a faulty MAF and carbon deposits in the cylinder to wrong temperature spark plugs. Now, the OEM ECU programming will retard the ignition timing if it detects pinging or knocking (way before you can actually hear it) even if you put 87 octane gas in by mistake, so the fact that it's an ongoing and recurring problem suggests an engine malfunction or problem of some sort.

Critter

Diabolis is correct, different stations have different additives placed in the gas at the depot, the name brands Shell, Chevron and the like have specific additives while smoking Joes discount fuel and many others will not. It is near impossible to get a computer controlled engine to "ping" whereas the older cars with distributers and fixed timing will ping under heavy loading and reduced RPMs, ie lugging. The computer pulls timing long before any detonation is audible. You state the service guy heard it, well then have him tell the techs to do diagnostics on the ECU, change it out or as others have done, tell your tuner what is going on and deduct timing from the tune. Your pinging could be just a heat shield rattle, EH!

AMG893

In my ML63, i used to use Nulon Pro Strength Octane Booster.
1 bottle per tank.
And i used to use it on EVERY FILL UP. I always run my tanks down.
http://www.nulon.com.au/products/Fue.../#.U4YIMZSSy0M

Thats the link to the product.
In Australia, we have 98 RON fuel (Shell V Power, etc)
This product, according to their website, will increase the 98 RON, in 60 Litres of fuel, to 100RON.
Mind you, the ML63 tank was 100L, so i expected the RON to be APPROX 99 RON.

Anyhow, i found with prolonged use [did this for about 6 months straight- yes, it wasnt cheap. Full tank on the ML63 costs about $180 + $15 each time for the Octane Booster] that the exhaust tips slowly changed colour.

Usually exhaust tips, inside of them, are Black from the carbon build up.
Well, slowly but surely, inside the exhaust tips started turning a gold/brown/yellow colour. Kinda rusty looking i guess. (if i had pics, would post them to take the guess work out of all my description!)

Anyhow when i noticed this, i thought it was a little odd, and maybe not good for the car. So i ceased using octane booster, and sure enough the tips turned black again.

At this point, i thought i should probably change the spark plugs, and when changing them, the plugs had a very similar colour on them. A kinda dry rusty colour, identical to the exhaust tips.

Car has OE Tune on it. Had the tune BEFORE using OCT booster- throughout- and after stopping using it.
(Ie- colour change in tips, had nothing to do with the tune)

Not sure where im going with this, but thought i would post it up, seen as though were talking about OCT booster.
Someone with more knowledge can comment, and probably tell me what the colour change is all about, and if it hurt the car.

AMG893

Oh, and FYI, here is a pic of the user manual fuel page (page 171) for the C63

zcct04

Shell (yes), Chevron (yes) Costco (?)
I would not have put Costco in the 'top tier' gasoline list. Does Costco really use similar additives levels?

bhamg

This product probably had MMT in it. I used an octane booster formulated with MMT as a primary ingredient for about 8 months in an M3. When we took the head off there were orangey-pink deposits inside the combustion chambers. I never noticed the inside of the tips changing color but IIRC the bottles were only 8 ounces. Needless to say, after seeing that I stuck to pump gas only.

whoover

I admire effective marketing as much as the next guy, and I wish the Top Tier consortium the best, but where do you think Costco gas comes from? They don't refine it in the back, behind the paper plates. It comes from the same refinery that the Shell or Chevron comes from. Blending is not done in little batches, like kettle potato chips. Refineries are 24-hour production lines, and they don't have a multitude of paths for different brands. The gas is blended with enough additives to meet manufacturers' and legal standards.

Yes, Shell or Chevron might toss in a little extra something at the end but there is no hard evidence that these extras have any real benefit. Of course Shell or Chevron says they do and spends enough money to make that message stick. But engine problems due to deposits are pretty rare in these days of lean-burning ECU-managed engines. Ask your tech.

whoover

From http://www.edmunds.com/car-care/is-c...-your-car.html

The Auto Club's Mazor was more forthcoming, and has some interesting results from a blind test he did on three samples of gasoline from both major and independent gas stations.

"We tested emissions, fuel economy and performance and we could not tell the difference," he says.

Mazor believes that the driving public has outdated notions about gas. Twenty years ago, only premium fuel had detergents in it. Back then, it was beneficial to occasionally buy a tank of high-test gas to clean the engine. Then, he says, "regulations were very lax and there was little enforcement. But all that has changed."

Likewise, Randy Stephens, chief engineer for Toyota's Avalon, isn't wholly convinced by the claims of engine protection afforded by higher-priced gas. He says fuel experts at his company study the effects of different brands of gas on the Toyota engines. Automotive engineers disassemble engines after 10,000 miles of running them on different brands of gas to see if there is a difference.

"Honestly, in the 10 years I've been in charge of Avalon, I've never seen one come back with any sort of deposit issue," Stephens says.

zcct04

Here's text from the 2012 US manual:

Premium-grade unleaded gasoline
! To ensure the longevity and full performance of the engine, only premium-grade unleaded gasoline may be used.
If there is no premium-grade unleaded gasoline available and regular-grade unleaded gasoline may be used; please observe the following precautions:
• only fill the fuel tank to half full with regular-grade unleaded gasoline and fill the rest with premium-grade unleaded gasoline as soon as possible.
• do not drive at the maximum speed.
• avoid sudden acceleration.
• if the vehicle is carrying a light load, e.g. two passengers without luggage, do not allow the engine to rev above 3,000 rpm.
• if the vehicle is fully loaded or is being operated in mountainous terrain, do not depress the accelerator pedal further than 2/3 of the pedal travel.

Fuel requirements
Use only premium-grade unleaded gasoline. The octane number should be at least 91. Details can be found on the gas pump. The octane number is the average value of the Research Octane Number (RON) and the Motor Octane Number (MON): (RON + MON) / 2, also known as knock resistance. Reformulated gasoline (RFG) and/or unleaded gasoline with additives can be used. However, the concentration of additives in the fuel must be less than 10%, e.g.
• Ethanol
• TAME
• ETBE
• IPA
• TBA
For MTBE, the concentration should not exceed 15%.

The concentration of methanol in gasoline including other additives must not exceed 3%.

Using mixtures of methanol and ethanol is not permitted. Gasohol, a mixture of 10% ethanol and 90% unleaded gasoline, can be used. All of these mix fuels must fulfill the fuel requirements, e.g.:
• knock resistance
• boiling point
• vapor pressure

Additives in gasoline
One of the main problems of poor fuel quality is the forming of deposits that are created during the gasoline combustion process. Mercedes-Benz recommends that you use fuel brands that have the additives. Deposits may form if you use fuels without additives over a longer period of time. These deposits are most likely to form on the inlet valves and in the combustion chamber. This could lead to engine problems, e.g.:
• longer engine warm-up phase
• uneven idle
• engine noise
• misfiring
• loss of power
Carbon deposits may form if the availability of gasoline with relevant additives is insufficient (in certain regions). In this case, Mercedes-Benz recommends the use of additives that have been approved for Mercedes-Benz vehicles.
Consult an authorized Mercedes-Benz Center or go to the Internet site http://www.mbusa.com (USA only) for a list of approved products. Comply with the instructions for use on the product label. Do not mix other fuel additives with fuel. This causes unnecessary costs and could damage the engine.

! Do not refuel with low-grade fuel and do not use fuel additives that are not tested and approved for Mercedes-Benz vehicles. Damage to or malfunctions of the fuel system may otherwise occur.

zcct04

Actually, it may be closer to kettle potato chips than you think. It's been a while, but the tank truck loading racks I used to support all received gasoline by pipeline from multiple refineries. They blended the stuff from every refinery into one big tank for each grade. When a truck showed up we loaded gas from that big tank, and as we loaded the truck we put in an additives package that was unique for each retailer.

bhamg

Not AMG but I have seen many M motors with the heads off. I lived within easy walking distance of my BMW dealer. My tech friends would call me when an M motor was getting worked on because they knew I wanted to take a look inside. Without exception I was always surprised at the extent of carbon buildup.

Me: "I'm shocked how much carbon I see here."
Service manager: "They all do that."

Critter

Most if not all of the carbon accumulation on pistons and valves is not from the combustion of the fuel but the additional oil fume from the PCV systems on modern cars. Oil is also drawn down the valve guides especially the intake valves on engines with worn valve train components. Many AMG owners have used a catch can to reduce the inhalation of the crankcase vapour with good results and with some steady runs on the highway ( long trips) if these engines were torn down the deposits would be minimal. The short stop and go driving most cars see only increases deposit accumulation, with lower cyl temps. IMO

zibby43

Haha! I definitely agree that Costco isn't making top tier gas somewhere at the back of aisle 3.

But actually, as I understand it, the addition of top tier detergents does occur in little batches. The tankers delivering fuel to various stations have individualized compartments. Thus, the detergents can be easily added to particular batches and then delivered to the proper top tier retailers.

You're not paying much more for the detergents, maybe a few pennies. And you're right, there hasn't been definitive "smoking gun" evidence that these fuels make a significant impact. Supposedly they help to keep injectors and valves free of carbon buildup, particularly on high-performance vehicles.

The fact that the cost is minimal, coupled with the potential payoff, is why I choose to use them.