My brother has topped up the oil on his St Mondeo from the min mark to full with the wrong oil Will it be ok or will it do the engine some damage?

 

Be fine

 

It's just he didn't know if the oil would be thicker and the pump wouldn't like it.
I thought it would be ok though, just wanted someone else to say so to.

 

How wrong is the oil? What did he put in?

 

He put in some 10w 40 instead of 5w 30

 

It should be ok, what he has at the moment will be thinner when hot (This is what the second number denotes, so 40 in this case) however I would personally change with the correct 5/30W reccomendation. Personally if it was that low I would have done a change anyway, it's also worrying how it was on minimum in the first place!

Martin

 

i would personally change it as my brother bought wrong oil for his oil change and that was 10w 40 and its stopped buckets working properly and eventually jammed buckets and ended up needing new engine

 

I wouldn't worry too much..... I work in the parts game and can tell you that it won't make any difference and definatly won't bugger ya "buckets" up..

 

Are you saying it doesn't matter what oil you put in an engine?

 

No.... I said that topping that car up with that oil will be ok..

 

I personally wouldn't be happy mixing oils and would drop it and fill with correct oil. It will probably be fine but I would want piece of mind for only a few quid. But that's only my opinion.

 

I have a similar "arguement" day in day out with people..... They ask me for oil for their car and I then get asked "anything cheaper"..... I tell them the right oil is xxxxx after that you can put what you like in but on your head be it.....


Steve

 

As engines get older the tolerances inside them get looser, and often its a good idea to move to a slightly thicker oil. So his 6w32 in there now is probably perfect!

It will be fine providing the oils arent actually incompatible chemically like if it was castrol R40 or something like that.

 

Lol@ 6w32.....

 

Steve I know how you feel I work in a motor factors and some people just won't listen when it comes to oil, they want the cheapest. I also get the muppets who ask advice then totally ignore it

 

Know the feeling I'm a manager at a motor factors.....

 

I'm assistant manager, me and my father in laws buisness partner (owners) run the business. It's a funny old trade lol

 

And I still wouldn't be happy or recommend anyone to mix or use the wrong oil, or say its ok to do either

 

Well theres one thing....... some oil is better than no oil at all lol

 

it will be fine

 

For short it will be fine but for longer he should use a better oil than 5W-30. Never mind what ford directs.

 

Better in what way?

He hasnt commented about the quality of the oil, this thread mentions only viscosity.

It could be esther synthetic or a mineral mix for all we know!

 

Right or wrong grade or type of oil,
If it was on minimum when he topped it up it won't be too long before it's gone and needs topping again, unless he's never topped it up


.

 

Ask some of the thousands of VAG 1.8Turbo engine owners that have lost an engine because of using something other than VAG approved synthetic, if the correct oil is important.

 

In heat-proof for example.

Never said that. I'm only willing to give oil tips, why not?
And a 5W-30 mixed with 10W-40 is crap for me, even for refill.

But if ppl want to maltreat their engines with crap oil, go ahead!

 

What are you on about?
His particular brand of 5w30 or 10w40 could be an estersynythetic capable of taking 160 degrees of heat for all you know.

The grade of the oil isnt its heat rating, its the viscosity (thickness) thats all.
You can get 10w40 oil that takes massive heat, and others that cant cope with heat at all well, but they still have the same thickness.


People actually deliberately blend oils to get to a viscosity they want for certain uses, include the oil companies in the first place, so I dont see how the fact its got two grades of oil in now somehow makes it "crap oil" what do you mean? Crap in what way?

 

mineral oils are crap for me (what most 10W-40 are)
• cold too thick
• hot too thin
• no additives (engine gets dirty, gaskets harden faster etc.)

 

Thats just total nonsense, the 10 refers to the cold temperature equivalent thickness, if its mineral or synthetic that is still true, the 40 refers to the hot temperature equivalent thickness, again for both mineral and synthetic.

So a 10W40 mineral would be thicker hot than a 5w30 synthetic if you were going to make the assumption that the 10w40 he has used was mineral like you seem to want to and that the 5w30 was a synthetic.
So it wont be "hot too thin" at all, in fact if will be thicker.

In reality though its very rare to see anyone selling straight mineral oil at all these days in 10w40, thats a grade you tend to find is normally semisynth if anything, but it could potentially be anything upto and including the latest ester synthetic.

In one of our trackdays cars for example I run 15W50 Motul 300V for example, thats a good quality fully synthetic oil ( Double Ester in fact) with a great additive pack and fantastic tolerance to high temperatures without breaking down, and yet you would dismiss its quality on ground of the thickness?

I really think you have completely misunderstood what the numbers actually mean, they tell you nothing at all about if its a mineral or a synthetic.

 

Both oils 5w30 and the 10w40 are semi-synthetic Halfords oil

 

I didn't know that they fitted those particular engines in Mondeos..... I know exactly how important oils are, but I answered the original question about a Ford on a Ford forum, not a VW, Audi, Seat or Skoda.

 

I stand by exactly what I said to begin with then, it wont make any difference that matters.

Oil is not an exact science, you making the 5w30 very slightly thicker by diluting it 20% with 10W40 isnt going to do any harm.