Mercedes & Gasoline - PeachParts Mercedes-Benz Forum

neznaika · #1 09-12-2007, 08:38 PM

I've read some totally useless threads. Pointless arguing.

I'm tired of people talking about their Fords, Chevys... etc. This is Mercedes forum! We want to know about Mercedeses!!! Here are the questions for Mercedes machanincs:

---Premium is the way to go for ANY Mercedes! Which brand though? We have Kwik (formerly Texeco). Any good?

---We have Shell, and they have V-Power with cleaning additive. That's what I use right now. Any good? I've heard some bad things about Shell.

---MAIN question: Can I use Kwik (Costco, Wal-Mart type of gas) and clean with Sea Foam from time to time, instead of using Shell?

P.S. Is any cleaning agent bad for Mercedes? Sea Foam is the best in cleaning, and calims no harm to cars. Is Mercedes any different? This is my first Mercedes.

PLEASE ANSWER ALL OF THE QUESTIONS! Any RELAVANT feedback is greatly appreciated!!!

brewtoo · #2 09-12-2007, 10:25 PM

I use BP, Racetrack, Exxon, Cowboys, Chevron...whoever has the best price.

I run a 50/50 mix of 87 and 93.

I have done this on our Mercedes thru the years for over a half-million miles. I never use Seafoam or any cleaner. I have never had any ill-effects.

Gas is gas. It all comes out of the same pipeline and the various retailers add (or don't add) their additives.

I also use Supertech oil from the Walmarts. Because it's cheap and oil is oil, IMHO. I had to pull the pan off our '90 because a professional mechanic dropped a ball socket into the engine and it eventually locked up the oil pump. The inside of the engine was spotless - no sludge or buildup of any kind. The car was sixteen years old. The oil managed to stay in the bearings and even though I drove it probably two miles with ZERO oil pressure before I noticed (I heard lots of noise) the engine was not harmed. I was amazed.

Perhaps someone else can fulfill your demand to answer ALL the questions.

BTW, would you like to tell us which Mercedes Benz model you own?

TMAllison · #3 09-12-2007, 10:28 PM

I believe all your questions are addressed in your owners manual. I know octane is as well as the use of additives. I think there may even be a recommended brand in there too.

TheEngineer · #4 09-12-2007, 10:57 PM

Most engines nowadays have knock sensors. It'll retard the timing if pre-ignition is detected. I have used regular Costco gas for years in my 280SL and the timing is set to factory specs. There is no pre-ignition. That car has no knock sensor. I suspect that the fuel dispensed is the same for regular and premium. Check your gas milage: If you use premium you should get about 2 more MPG. It's supposed to have more energy content.

mpolli · #5 09-13-2007, 12:04 AM

Quote:

Originally Posted by TheEngineer

If you use premium you should get about 2 more MPG. It's supposed to have more energy content.

WRONG!!! This is the oldest of old wives tales. Octane is a measure of knock resistance ONLY!!

Mike

joselu43 · #6 09-13-2007, 12:19 AM

But, for a number of reasons you still may get better mileage. This is a complex issue and there is no simple answer. That is why we have so much (anecdotal) contradictory evidence. Also, some high octane gasolines do have higher energy content.

Jl

mpolli · #7 09-13-2007, 01:21 AM

A high compression engine will generate more power with high octane fuel than with low octane fuel, however this has nothing to do with the energy content of the fuel. If anyone would like you to belive high octane fuel has "more energy" it is the oil comanies right? Here is what Chevron has to say about it:

"Don't Buy a Higher-octane Gasoline to Improve Fuel Economy

Octane and energy content are not related. Premium-grade gasoline doesn't necessarily have a higher energy content, especially if it is oxygenated.

The exception to the above advice is when a lower-octane gasoline doesn't satisfy the octane requirement of the vehicle's engine. The abnormal combustion that announces itself as knocking reduces engine efficiency. Using a higher-octane gasoline that eliminates knocking will improve both engine performance and fuel economy.

Many newer vehicles with an electronic control module (ECM) also have a knock-sensor device. When the sensor detects knocking, the ECM retards the engine's ignition timing to eliminate the knocking. This happens so quickly that the driver never hears the knocking. But retarding timing decreases power and fuel economy. A higher-octane gasoline may improve the performance of knock sensor-equipped vehicles that have less power than when new."

I question their last statement, but they are trying to sell the stuff right? It is a classic "might" claim. "might", "might not".

Here is the link:

http://www.chevron.com/products/prodserv/fuels/bulletin/fuel_economy/

Mike

tvpierce · #8 09-13-2007, 05:45 AM

Quote:

Originally Posted by neznaika

I've read some totally useless threads. Pointless arguing.

I'm tired of people talking about their Fords, Chevys... etc. This is Mercedes forum! We want to know about Mercedeses!!! Here are the questions for Mercedes machanincs:

---Premium is the way to go for ANY Mercedes! Which brand though? We have Kwik (formerly Texeco). Any good?

---We have Shell, and they have V-Power with cleaning additive. That's what I use right now. Any good? I've heard some bad things about Shell.

---MAIN question: Can I use Kwik (Costco, Wal-Mart type of gas) and clean with Sea Foam from time to time, instead of using Shell?

P.S. Is any cleaning agent bad for Mercedes? Sea Foam is the best in cleaning, and calims no harm to cars. Is Mercedes any different? This is my first Mercedes.

PLEASE ANSWER ALL OF THE QUESTIONS! Any RELAVANT feedback is greatly appreciated!!!

Pretty demanding considering you're asking strangers for free advice.

Rules of society do still apply on the internet -- in my humble opinion.

t walgamuth · #9 09-13-2007, 06:03 AM

Not all gas benzos call for premium.

My 84 500SEC used RUG. It was one of the reasons I bought it. At those prices it was fairly close to the operating cost of a diesel on the highway since Diesel costs more per gallon.

I tried to avoid a steady diet of cut rate stations and used a bottle of cleaner every five or six tanks full.

Tom W

MB-Dude · #10 09-13-2007, 09:35 AM

Quote:

Originally Posted by neznaika

I've read some totally useless threads. Pointless arguing.

I'm tired of people talking about their Fords, Chevys... etc. This is Mercedes forum! We want to know about Mercedeses!!! Here are the questions for Mercedes machanincs:

---Premium is the way to go for ANY Mercedes! Which brand though? We have Kwik (formerly Texeco). Any good?

---We have Shell, and they have V-Power with cleaning additive. That's what I use right now. Any good? I've heard some bad things about Shell.

---MAIN question: Can I use Kwik (Costco, Wal-Mart type of gas) and clean with Sea Foam from time to time, instead of using Shell?

P.S. Is any cleaning agent bad for Mercedes? Sea Foam is the best in cleaning, and calims no harm to cars. Is Mercedes any different? This is my first Mercedes.

PLEASE ANSWER ALL OF THE QUESTIONS! Any RELAVANT feedback is greatly appreciated!!!

For my gassers, I always run premium. I can tell you absolutely and definitively that *all* my gasoline cars run better on 93 octane premium in Texas as opposed to 91 octane premium in the Bay Area of California. Same brand - Chevron. I generally default to Chevron though do occasionally put a different brand in the tank. Though I use ‘off-brands’ very sparingly. I always fill the tank, regardless of brand. There may be a lot of marketing hype with Chevron, but I’ve had a couple unrelated indies recommend Chevron over the years.

I do believe gas-is-gas for the most part and basic octane levels must be the same, brand-to-brand. However, off-brands are off-brands for a reason. Not sure why, but believe they may not have the additives or purity; i.e.: moisture content, suspended solids, etc. I would be interested in reading the thoughts of others regarding this. I would imagine each of the big-guns (Chevron, Texaco, Shell, Union 76, Phillips 66, etc.) are similar in product quality. However, to my knowledge, only Chevron discusses a chemical additive (Techron) while the others (Shell, in particular) just talk about marketing slogan; i.e.: V-Power.

I choose Chevron for the quality and consistency of the product. Yes, I pay a few cents more per gallon. But even if the tank in my SL600 is bone-dry empty, a full tank is only - worse case - $2.00 more than the cheapest off-brand. And at the base price of premium today, that’s a rather small percentage of the total fuel bill. Why not pay a few cents more for quality and consistency of product? I think I can afford up to $2.00 extra per tank for peace of mind and good performance.

Every 4 tank-fills, I add a can of Techron, even if I've been filling with Chevron. I like the cleaning ability of Techron and, according to the Factory Approved Service Products (as of) September 2006, page 15, Mercedes now authorizes one of two gasoline additives – MB product p/n: 000.989.25.45.12 or Techron Concentrate Plus Fuel System Cleaner (588 ml, 20 fl oz container). I track my MPG carefully for all my vehicles and I do see an MPG jump of 1-2 MPG immediately upon adding the Techron additive. Each tank-fill after that, the MPG drops a little. After 4 tanks, I repeat the process. My plugs come out clean and using a bore-scope shows very clean cylinders and piston heads on the SL’s. (Haven’t changed the plugs yet in the ML.) I believe the Techron does help – it’s not a wonder cure-all and it won’t instantly make your car a Batmobile, but over time the product does have a positive effect.

I have not used SeaFoam… yet. However based upon threads in this forum, I purchased a can of SeaFoam but have not used it yet. I have used other additives over the years, some with dubious or marginal success. I always seem to come back to Techron.

BTW – I do not work for Chevron; never have. In my professional career I managed high-tech engineering organizations – no affiliation with the auto industry, other than a love for Mercedes motorcars.

Cheers,
Jeff

G-Benz · #11 09-13-2007, 09:46 AM

I've run 93 octane Shell premium on all of my vehicles since ownership...no fuel related issues as far as I can tell. When I do travel further north, 91 octane is the highest available and I use that.

And octane is a measure of "flash point", not energy content or anything else. Translated, it takes a higher temperature to ignite the atomized fuel in the combustion chamber. That means, it won't "pre-ignite" in the compression cycle or "knock" as what it is normally referred to.

This is why turbo gas engines require premium.

TMAllison · #12 09-13-2007, 10:08 AM

Quote:

Originally Posted by MB-Dude

I like the cleaning ability of Techron and, according to the Factory Approved Service Products (as of) September 2006, page 15, Mercedes now authorizes one of two gasoline additives – MB product p/n: 000.989.25.45.12 or Techron Concentrate Plus Fuel System Cleaner (588 ml, 20 fl oz container).
Cheers,
Jeff

Jeff - Is there any recommednation in that document conerning Diesel fuel additives?

Moneypit SEL · #13 09-13-2007, 10:46 AM

Quote:

Originally Posted by mpolli

A higher-octane gasoline may improve the performance of knock sensor-equipped vehicles that have less power than when new."

I question their last statement, but they are trying to sell the stuff right? It is a classic "might" claim. "might", "might not".

Here is the link:

http://www.chevron.com/products/prodserv/fuels/bulletin/fuel_economy/

Mike

Well, it could happen. If the vehicle ECM in question is programmed to advance timing beyond specification untill knock is sensed. Very few cars do this. The vast majority start at factory spec and retard timing whenever knock happens.

juribe2 · #14 09-13-2007, 10:49 AM

Quote:

Originally Posted by G-Benz

..... Translated, it takes a higher temperature to ignite the atomized fuel in the combustion chamber. That means, it won't "pre-ignite" in the compression cycle or "knock" as what it is normally referred to.

This is why turbo gas engines require premium.

It's not about temperature. It's about compression. Higher octane means it needs more compression to ignite without a spark (pre-ignite). Using higher or lower octane depens on engine compression relation and hight above sea level. You need high octane when at sea level and can use (or mix) lower octane on high locations. Engines with compression relations under 10:1 usually work good with regular fuel.

MB-Dude · #15 09-13-2007, 10:49 AM

Quote:

Originally Posted by TMAllison

Jeff - Is there any recommednation in that document conerning Diesel fuel additives?

Sorry Terry, there is nothing listed - yes or no - as to the use of diesel additives in MB diesel engines. In fact, this is all there is on diesel engines in the entire document...

{Start of cut-and-paste from the Factory Approved Service Products September 2006 bulletin}
Diesel Engines Diesel Engines as of model year 2007 All diesel engines require S15 Ultra Low Sulfur Diesel (ULSD) fuel (15 ppm Sulfur maximum). Failure to use ULSD fuel can severely damage the vehicle’s exhaust after-treatment device. Refer to Product Information (page 14) for a sample of diesel fuel pump labeling.

Diesel Engines - Model year 2006 and prior Use only commercially available vehicular diesel fuel number 2 or number 1 (ASTM D975 Number 2-D or Number 1-D).

As of model year 2005 For information on cold weather operation, refer to the vehicle Operator’s Manual.

Pre-model year 1999 For information on cold weather operation, refer to the vehicle Operator’s Manual or Service Information MBNA 00/7(11-82).

B5 Biodiesel
Mercedes-Benz USA, LLC approves the use of B5 biodiesel (standard diesel with a maximum of up to 5% biodiesel content) in all Common Rail Injection Diesel "CDI-engines." Diesel fuels containing a higher percentage of biodiesel content will cause damage to your engine and are not approved.

As biodiesel can be refined from a variety of raw materials resulting in widely varying properties, the only approved biodiesel content is one that meets ASTM D6751 specification. It must also have the necessary oxidation stability (min. 6h, proved with EN14112 method) to prevent damages to the system from deposits and/or corrosion

Please ask your service station for further information. If the B5 biodiesel blend is not sufficiently labeled to clearly indicate that it meets the above standards, please do not use it. The Mercedes-Benz limited warranty does not cover damage caused by the use of fuels not meeting Mercedes-Benz approved fuel standards.
{End of cut-and-paste}

I would upload the .pdf file (393k), but file size restrictions of this site prohibit it.

Cheers,
Jeff