Fuel fillers being used at the pump - PeachParts Mercedes-Benz Forum

jbach36 · #1 08-30-2009, 01:25 AM

Heads up for gas cars, not sure about diesel fuel.

I've been hearing from a few people, all separate of each other, that they EVENTUALLY noticed their MPG is down on their cars. Wondering what was wrong with their cars, they checked mpg, and found it was quite a bit less than usual.

One lady said she switched fuel stations and her mpg went back up. Turns out, some of the fuel stations are using sort of a "gasoline helper" in their fuel. One lady suspected they're putting ethanol in the gas.

I've noticed recently my car starts just a tad funny, a bit rougher than usual, so maybe they're using "diesel helper" too, something as a filler so the stations can make more money.

Anyone else heard about this?

jeff 1991 300d, 137k

kingdoc1 · #2 08-30-2009, 05:26 AM

Most gas stations have notices posted that say the fuel may contain up to xx% ethanol. This has been common practice for several years. I think it is a requirement to post such a notice.

The gas at all the local gas stations comes out of the same large regional distribution tank, so whether you buy at Hess, Exxon, Shell, BP, etc., you are getting the same gas, you just pay more for it some places. Some companies dump a little additive in it after it goes in their underground tanks, so they can say it has "superior cleaning power" or whatever, but gas is gas, it all comes from the same tank.

nhdoc · #3 08-30-2009, 08:09 AM

ethanol is used to "oxygenate" the gasoline. Since MTBE was removed they needed something to replace it for smog reduction and this is what they use and yes, it does have an adverse effect on the fuel economy in gasoline burners. Because it relates to smog, in some places it is mandatory and in some it is not so it is possible to find lower concentrations in more rural areas.

It is NOT added to diesel fuel.

Diesel911 · #4 08-30-2009, 01:10 PM

Due to lack of staff the Department of Weights and Measures in CA cannot police enough of the Service Stations to insure that they do not cheat you in reguards to the quanity of fuel that you get comming out of the Nozzle.

There has been several News reports on it; they filmed one place that had an extra set of controls to manipulate the Fuel Quanity that came out of their pumps.

Jeremy5848 · #5 08-30-2009, 04:18 PM

Some diesel sellers are adding small amounts of biodiesel (2% - 5%) in the belief (and it may be true) that it makes up (in lubricity) what ULSD lacks. Given that the biodiesel industry is barely out of diapers, it is possible that a careless fuel seller could get a bad batch and contaminate his tanks.

I buy almost all my fuel from "Rotten Robbie," a local chain here in NorCal. They sell a biodiesel blend, B20, which I have used for a year with no problems. Our diesels get better fuel economy on B20 than on B100 and 20% biodiesel is enough to get rid of the diesel "stink" (my wife's word, YMMV). Then again, I know the source of the biodiesel that they use in the blend, so I have no worries.

Jeremy

compu_85 · #6 08-30-2009, 04:56 PM

Does fuel lubricity make that much of a difference on a MB? I know it does on a car with a VE pump, but I don't know how much of an inline pump is lubed by the fuel.

When I got my best economy ever in my TDI I was running B15 (56.8 MPG!)

-J

probear · #7 08-30-2009, 06:50 PM

Quote:

Originally Posted by Jeremy5848

Some diesel sellers are adding small amounts of biodiesel (2% - 5%) in the belief (and it may be true) that it makes up (in lubricity) what ULSD lacks. Given that the biodiesel industry is barely out of diapers, it is possible that a careless fuel seller could get a bad batch and contaminate his tanks.

I buy almost all my fuel from "Rotten Robbie," a local chain here in NorCal. They sell a biodiesel blend, B20, which I have used for a year with no problems. Our diesels get better fuel economy on B20 than on B100 and 20% biodiesel is enough to get rid of the diesel "stink" (my wife's word, YMMV). Then again, I know the source of the biodiesel that they use in the blend, so I have no worries.

Jeremy

Also, as ironic, even that small of percentage of Bio-Diesel significantly reduces pollution by a far greater percentage than the mix would suggest.

Diesel911 · #8 08-31-2009, 12:46 AM

Quote:

Originally Posted by compu_85

Does fuel lubricity make that much of a difference on a MB? I know it does on a car with a VE pump, but I don't know how much of an inline pump is lubed by the fuel.

When I got my best economy ever in my TDI I was running B15 (56.8 MPG!)

-J

In Inline Fuel Injection Pumps the Elements/Plungers and Barrels that create the high pressure for the Injectors are lubricated by the Fuel. All the other parts are lubricated by Oil supplied from the Engine or if your Fuel Injection Pump is old enouh you add the Oil to the Fuel Injection Pump yourself and you have to check it ounce in a while for contamination or to maintain the Oil level.
Rotary pumps like used on GM,VW, Volvo and so on are all lubricated completely by the Fuel. They also are sealed by way more O-rings and have seal/s on their drive shafts that some have claimed the new Diesel Fuel has done in.
The Fuel Injection Pum Drive shaft seal on My Volvo started leaking about 1-1/2 years ago. Was it the new diesel or old age?