Originally Posted By: cmf
Our gas is a little dirtier than in Europe, which contributes to our oil change interval being slightly shorter. By dirtier I mean we still have some sulfur in our gasoline while it's nearly eliminated in Europe (our limit is 80 ppm per gallon with 30 ppm yearly average). The sulfur adds to emissions as well as forming sulfuric acid.
It definitely is not dirty enough to necessitate 3,000 mile oil change intervals. I think he is living in the past where our gasoline was much "dirtier". The new limit came into effect in 2006 and the most substantial lowering came into effect in 2000.
If anything, the sulfur in our gasoline is more of a problem for advanced emission systems than it is for oil.
Longer oil change interval in Europe is not because of the fuel, but because in Europe, Synthetic Oil is truly Synthetic.
(Group IV or V). In the US (don't know about Canada), what we call Synthetic is mostly super refined stuff that comes out of the ground (Group III) which does not last as long as the Group IV and V from Europe. Even the M1 sold in Europe is different than the M1 sold in the US.
Whenever I lease (not rent) a car in France, I see that they call for an oil change every 30,000 km (18750 miles). Can't remember if my Laguna's said that they recommended Total or Elf.
BTW, what ever happened to M1's adverts that said M1 can go 25,000 miles, or the one where M1 and another brand were placed in a frying pan, showing the other brand heating up and boiling off, while the M1 stayed fluid. Was the old M1
(Group IV) better than the new M1 of whatever Group it is now?
Years ago, my boss, a Chemical Engineer who swore by M1, would change his M1 oil once a year in his Honda Civic. Changed every springtime. Every 8000 miles, he would change the filter, then add just enough M1 to make up for the oil in the filter. He kept good records, and he was changing that M1 about every 25,000 miles, once a year. Swore by the stuff.
Never had a problem with that Civic.