will adding a quart of SW50 mess up your car if the reccomended oil is SW40?

Question

i added a quart of SW30 and a quart of SW50 because that is all that was available... do the oils meld or stay separate in the engine?

Answer 1

It's not good to mix oils, but I don't really see doing any harm to your engine. Just put the recommended oil in and change your oil and filter when due.

Good Luck

Answer 2

Here's the CORRECT answer. Adding the different weight oil will not harm the engine; the oils will mix together and do an adequate job of lubricating the engine. When it's time for your next oil change I'd use all the same weight however.

The thing that concerns me in your question though, is the fact that you had to add 2 quarts... this means one of 3 things:

a) You have really worn piston rings which are causing oil blow-by and cause your engine to burn oil (this should be evident by blue smoke from the exhaust). If this is the case, a ring job is the only cure; a temporary fix is to buy a couple of bottles of oil thickening agents like Motor Honey, CD2, etc. which will lessen the problem temporarily...but you'll keep having to add the stuff at every oil change.

b) You have a major oil leak (oil pan leak, loose or stripped pan plug, or leaky/blown engine seals somewhere). You should be able to determine this by looking at the ground where you usually park the car...a small puddle's a dead giveaway. The fix...cheap or expensive depending on what's wrong. New oil plug...cheap. Replacing blown seals/gaskets....potentially pricier. Again, there's a "solution in a bottle" for leaky seals as well, but if it's a major leak these things won't work.

c) You don't change your oil but rather just add new oil as the engine consumes it. I hope this isn't the case as your vehicle won't last long this way. Old oil has metal particles and sludge which will eventually ruin an engine, not to mention your oil filter will eventually plug up from it, leading to a later potential disaster.


I'd take the car to a competent mechanic and have him analyze the problem...then you can decide whether it's worth fixing.

Hope this helped a little.

Answer 3

it will probably take longer to burn putting stress on the engine. no man they cancel each other out, they will mix, but your engine is going to ok, as long as this was a one time deal. don't mess with an engine they can be expensive to fix

Answer 4

if you had to add 2 quarts your due for a change or a leak repair

Answer 5

not a problem. also, any oil better than no oil.

Answer 6

Don't you mean 5W50 and 5W40?