Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Using the wrong oil in a car

  • 28-01-2012 3:35pm
    #1
    Jimmy Bottles
    Registered Users, Registered Users 2 Posts: 349 ✭✭


    My car takes 5w30. Just wondering but how damaging would it be to use 10w40 in an engine which is designed for 5w30 ?

    On another point, how about topping up an engine with say half a litre of the wrong oil. I had to do this a few years ago. I thought at the time that the wrong oil was prob better than too little.


Comments

  • #2
    tossy
    Registered Users, Registered Users 2 Posts: 9,593 ✭✭✭tossy


    Jimmy Bottles wrote: »
    My car takes 5w30. Just wondering but how damaging would it be to use 10w40 in an engine which is designed for 5w30 ?

    On another point, how about topping up an engine with say half a litre of the wrong oil. I had to do this a few years ago. I thought at the time that the wrong oil was prob better than too little.

    Short term to get you out of a whole wrong oil is always better than none/too little oil.


  • #3
    Kavs
    Registered Users, Registered Users 2 Posts: 293 ✭✭Kavs


    Sorry to thread hijack, but its funny you posted this I was just about to ask the same question, story is I was changing oil in my car today 02'VW passat tdi. I had 3litres of Castrol 5w40 (505 01 spec) left over from previous service so bought another 4l today only to find out I bloody picked up the wrong can 0w40 (505 00 spec) Was it okay to add 0.5l of this with the 5w40 (505 01)???

    thanks.


  • #4
    An Ri rua
    Registered Users, Registered Users 2 Posts: 4,546 ✭✭✭An Ri rua


    Yes, its ok to mix oil nowadays so long as the majority of the oil is the correct spec.

    It was always the advice a few years ago that you didn't mix, that you didn't go back to mineral after using synthetic etc etc. despite the fact that most of the 'synthetic' was blended synthetic.

    This should put your minds at ease http://www.popularmechanics.com/cars/how-to/products/4213451


  • #5
    Kavs
    Registered Users, Registered Users 2 Posts: 293 ✭✭Kavs


    I hope so, I know these engines are very sensitive to the wrong type of oil.
    Can't believe I picked the wrong can off the shelf! so annoyed.:mad:


  • #6
    Jimmy Bottles
    Registered Users, Registered Users 2 Posts: 349 ✭✭Jimmy Bottles


    Did a bit of read.

    Read that 0W30 oil is thinner than 5w30 or 10w40 and will give you better power but a bit more wear. Going for 15w40 will give you less power but better engine protection.

    Is it that a car recommended oil is nothing more than a recommendation or that using the wrong oil entirely is seriously bad for your car ?


  • Advertisement
  • #7
    An Ri rua
    Registered Users, Registered Users 2 Posts: 4,546 ✭✭✭An Ri rua


    Jimmy Bottles wrote: »
    Did a bit of read.

    Read that 0W30 oil is thinner than 5w30 or 10w40 and will give you better power but a bit more wear. Going for 15w40 will give you less power but better engine protection.

    Is it that a car recommended oil is nothing more than a recommendation or that using the wrong oil entirely is seriously bad for your car ?

    You're referring to the viscosity. The flow of the oil.

    Yes, recommended oil is exactly that. Recommended. Using a full sump of the wrong oil is NOT recommended. The oil viscosities are chosen based on engine performance, operating conditions etc. if you put all 10w40 in a car seeking 0w30, it will longterm overheat and do damage if you are pushing it on. Also on cold starts, you'll be killing it.

    ALWAYS go with the recommended spec. Not necessarily brand preferred by car maker. But spec.


Advertisement