oil ? - boyracer
Can you tell what damage could be done by topping up an engines oil level with fully syn oil (say RS or Mobil 1) which has semi syn oil in it ??????

PS the engine is a ford 1800 zetec
oil ? - THe Growler
This was a hot topic during our recent Bike Week. Short answer is no damage. You can mix synth with fossil oil as well according to the adviser on the Shell stand at our expo. But this should be regarded as a short term application and oil should be changed before too long. Mixing types and viscosities is not a good idea. You can move up from fossil thru semi to full synthetic but not advisable to go the other way.

If you have already mixed semi and full don't worry, just get it changed as soon as convenient.
oil ? - marty lad
anyone out there heard of "estuary" oil?
oil ? - Fat Bald Man
I have a zetec engine and i had a trip to my local Halfords.If my memory is correct they advised only to use the 5W/30 oil as this is what Ford put in.
I do not know what the grade is of your oil but my mate in the trade states that the oil sensor detects the oil pressure upon starting and itf it aint right it will not start.Unfortuntely it could start after the service and run fine for a period but if it does not start only a Ford dealer would pick the problem on their computer and not your local mechanic.Just a thought

I wonder why you need to top up.Mine uses no oil whatsoever and it gets thrashed.
oil ? - DavidHM
No damage, long term, assuming you change the oil regularly. Ford engines do have a reputation for being fussy about the oil they use, Rapid Fit changes are cheap and even the OE oil from the dealer isn't more expensive than the stuff in Halfords (~£4/litre) so this isn't a real world problem.

If you're at all worried, phone your local Rapid Fit (that's the fast fit attached to most larger Ford dealers) and get a quote for an oil change. I've seen it as low as £15 using the original 5W30.
 

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