simoniz
Member Since: 28 Oct 2007
Location: The green green grass of home!!!!!
Posts: 3755
  
|
Accidentally used 5w/40w to top up my oil - used about 1 litre !!!. Big question is whats the implications,will it mix in ok with the correct oil already in the vehicle and will it impair the oil efficiency overall in the engine by much??
Responses folks as soon as if you can.
Feel a right t  t 
|
 12th Aug 2009 7:33 am |
|
|
|
|
PaulP
Member Since: 04 May 2007
Location: Barcelona
Posts: 4317
|
I wouldn't worry about it Si 
Despite what some would say, you can mix oils of different viscosity - the end result, once the oil has mixed with the engine running, will be an oil somewhere between the two original viscosities.
It's not a linear mix (for example, 50% 5W-20 and 50% 5W-30 will not give an exact 5W-25) but it works something like this....the fact that you only added 1 litre to get it up to the correct level means that your mix will be 1L 5W-40 and around 4.5L 5W-30 so it shouldn't affect it too much. Also, you added an oil with a similar viscosity and not something completely different (e.g 20W-50).
Some competition/old/special engines need hard-to-get grades of oil and people often mix different grades to get what is needed in terms of viscosity.
There is also talk that you should never mix different brands or oil types (i.e. mineral, synthetic, semi-synthetic). Common sense dictates that this is correct, but in theory, these oils will still mix fine and not cause any chemical instability in the oil.
Saying that, whatever you mix in will change the composition and properties/protection of the original oil and if the TDV6 was designed for 5W-30 synthetic then this is the correct weight/viscosity oil to use to ensure that the engine is working and protected as it should be.
What I mean by all this rambling is that I wouldn't worry about it in the slightest assuming that you only put 1L in and that it is the same type (i.e. fully synthetic) as the manufacturers recommended type.
Obviously I couldn't recommend doing this on a regular basis, but I think you can relax 2006 Discovery 3 TDV6 SE Auto Buckingham Blue
2007 Golf GT DSG
|
| 12th Aug 2009 8:02 am |
|
|
simoniz
Member Since: 28 Oct 2007
Location: The green green grass of home!!!!!
Posts: 3755
|
Thanks guys - really appreciate the swift replies to my dilema.
Feeling a little calmer now 
|
| 12th Aug 2009 11:40 am |
|
|
