I have had a drive-ability problem for a long time with a Jag I own and have often theorized water in the tank.

Three weeks ago my neighbor got gas at a local Sam's Club (same place I get 98% of my gas) and he had drive-ability
problems. He put octane boost in, started getting gas at another station, used gas cleaner and two tanks later his car started running well again.

This weekend I filled my 1995 DeVille with 18 gallons at the same Sam's Club, drove across the street to the grocery store. When I came out the car started sputtering and is running bad. I put cleaner/dryer in but haven't run through several tanks. It has a rough idle and chugging. Plugs, wires and coil packs are two years old @ 16,000 miles on them.

My 86 year old mother drives an old 1985 Lincoln. Lately her car is doing the same as all the above cars. Sputtering, no real audible missing but runs terrible. She doesn't get Sam's Club gas. Put she does use premium. I use Premium in the Jag and Caddie. The Caddie is OBDII and if it was a mechanical problem, I would get a code.

I am wondering of there is a problem with Premium sitting around too long and the ethanol's hydroscopic property is creating phase separation to the aging gas in the station tanks. Not as many people use premium as they do regular.

I am not thrilled with the 10% ethanol that is now required by law to be added to the gas. Could we be looking at ethanol water/separation problems?

As more ethanol is introduced to the supply chain, handlers need to be aware of potential conditions like "phase separation.

http://www.thepeijournal.org/content/3q07/af-
handlingethanol.php

Water and ethanol blends
http://www.thepeijournal.org/content/3q07/af-
handlingethanol.php

Other problems with government mandated fuel requirments are ruined fuel pumps

Fuel problem due to a drop in lubricity
http://www.caller.com/news/2008/oct/...s-suffer-with-
less-sulfur/

If you are a boater with older fiberglass tanks.....beware that you must use additives.

 

I don't want to come across as rude but lets recap. You have two very high end automobiles and your buy gas a Sam's Club.

I think your answer is right there in my one sentence. I only put three brands of gasoline in my tank. 91 octane or better, Sunoco, Shell and Esso in that order.

 

No not rude but as I posted to a Jag forum............

We have no tier 1 gas stations within 11 miles. All we have are Grocery store gas, convenience store stations, Sams Clubs and BJ's. So it comes down to which bad station do I want to use today? Our last Sunoco station closed a year ago, the BP station was torn down last year, Texaco.... can't remember seeing one in years, Shell ...never had one.....Esso. I haven't seen an Esso since I was a kid. I"m now 56. I remember the flying red winged horse. There aren't even any of the unknown, no-name independents around.

My wife used to commute 30 miles and there were tier 1 stations in that city but lost her job in Dec. 2006.

If I had extra time to make the 22 mile round trip to the closest Sunoco station, I would do it.

 

Sorry, that's what I get for living in the 5th largest city in North America. Esso is probably just sold in Canada. You are in a jam there. Bad gas is everywhere though. Maybe you could double filter it, we do this on our old muscle cars.