Motor oil... can I use 10w-40?

in my car?? It leaks a little oil and I thought that the higher weight oil would leak less than the lower weight oil. Is this true? I use 10w-30 oil at the moment and live in the north east where it gets cold in the winter.

ONLY ANSWER IF YOU ARE MECHANICALLY INCLINED AND ACTUALLY KNOW WHAT YOU ARE TALKING ABOUT!!

13 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    It won't change your oil leak rate.

    Check the recommended oil in your owners manual. A lot of the cars made now have tighter tolerances and many recommend 5w-30. Living in the northeast its best to use this weight oil if it's recommended.

    I live in the northeast too.

    You may not see any difference between adding the different wieghts and friends used to the 10w-30 and 40 may have a hard time breaking old habits, but when your engine fails how do you know you shouldn't have gotten another 30,000 more miles out of it?

  • 1 decade ago

    If you have a leak the 10W-40 would still leak. I use 10w-40 in the summer and then toward fall I change to 10w-30. When I lived in Northern Minnesota I used 5W-20 during the winter. This was at Bemidji where we would be coldest in the nation at times. I now live in Southern Iowa and I used 20w-40 all last winter. I have a small tractor that I use for plowing snow and I use 50 weight racing oil in that. The reason for that is that I use it for mowing in the summer too. Now if you use a synthetic oil things are a little different. You can get by with Mobil One year round, but it would be expensive to use if you have a leak. If the leak is easy to repair then fix it. If you need the engine tore out to fix iit then I would put up with it.

  • Anonymous
    1 decade ago

    The viscosity of the oil (10w-30/40/50) wouldn't have any bearing on whether your car leaked oil. It is more for temperatures (engine temperature and regional temperature). When I lived in the northeast I used 10w-40 all the time.

    Oil leaks could be caused by alot of things. First check where the leak is coming from? If it's from the top, it may be a bad valve cover gasket.....from the bottom, it may be a bad oil pan gasket or the plug (bolt where you drain the oil) may be loose.

    You could buy something like motor honey (or something similar) which might help to reduce the leak. But changing grades of oil wouldn't have much effect.

  • wzzrd
    Lv 5
    1 decade ago

    It will not help at all but you will loose gas mileage from the thicker oil. The 10 means it acts like 10 wt. in the winter (10w) and the 40 means it is 10 points higher than 30 on the viscosity scale. This only means that it will take more fuel and horsepower to move the oil though the motor. It will not be a large difference but it will be there.

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  • Anonymous
    1 decade ago

    Yes you can use it it will not cause any problems. I often use 10w-40 in my car. For the oil leak it will often get worse over time, and it won't matter what grade of oil you use it will still leak.

  • Skinny
    Lv 4
    1 decade ago

    It is thicker and in theory should leak less but if it is a leak it will still leak out either way, just be weary in the winter as a thicker oil is going to be harder to start in cold weather too...I recommend getting the seal replaced.

  • 1 decade ago

    The colder it is the thinner oil your engine needs, because its thicker at start up, Manufacturer probably calls for 5w30, i would fix my oil leak and run the recommended weight oil. The thicker oil WILL NOT HELP the oil leak.

    Source(s): Chrysler Dodge Jeep Tech
  • 1 decade ago

    10w-40 is for more demanding high reeving engine in hot climates. in no way will this oil grade switch improve your oil leak. it could be something very minor. but take it to your mechanic before it becomes something much more serious.

  • 1 decade ago

    Weight of the oil you describe is 10wt. that protects like a 30wt. and you want to switch to a 10wt. oil that protects like a 40wt. Zero Sum Gain. please get the leaks fixed after november things will get busy and cold you might not check your oil and run out causing damage to the motor

    Source(s): Nissan Master Technician
  • 1 decade ago

    No! that will not help. If you have a leak the only way to really fix it is to replace the gasket that is leaking.

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