Mobil1 5w-50 instead of Mobil1 5w-30 in a duratec

[tmrmathias]

Hi! I found this higher VI mobil1 oil really cheap, and as i am about to change filter and oil, i wonder if it would make any difference? The engine is a duratec 2.5 L v6, the high output SVT/ST200 engine.

I drive it hard, often rev to the red. The engine has gone 300,000 km or about 190k miles.
No noice, no nothing from the engine bespite at the purchase the previous owner had driven it for som while with 3l less than needed with oil, had to fill 3l until it hit max on the dipstick, so it was around 2l in it, when it needs 5, 7l.

Real einstein that one..

So, will it make any difference? At the moment its summer here, of course i will change when the temperature drops.
Is it good for summer oil? Good for winter oil?

The only difference between viscosity, the cheap doesn't have api sn, just sm.

Best regards

 

[RiceCake]

Yep. It'll make one difference and nothing else.

Sap your fuel economy.

 

[CATERHAM]

It will be way too heavy for your Ford Duratec engine unless you can blend it with some high VI 0W-20 such as the Toyota 0W-20.

 

[tmrmathias]

Okay, is the duratec extra picky about theVi or is this just something regarding all engines?

 

[CATERHAM]

It's not the VIthat's overly important but rather the HTHSV rating of the oil. M1 5W-50 has a HTHSV of 4.4cP, typical of a 50wt oil.
This means the oil will be way too heavy not just on start-up but at normal hot operating temp's (you're oil pump will never get out of by-pass at high rev's, not a good thing.

So if you can get a super deal on the M1 5W-50 buy it, but you'll have to thin it out will a light 20wt oil in a 2 to 1 part 50wt ratio. This will make a suitable 5W-30.

 

[shDK]

i know from a mate who works at a local ford dealer, they use 5w-40 in the ford petrol engines except the older zetec engines that should be rather picky. something to do with the hydraulic lifters . i believe that the summer in Sweden and Denmark are pretty similar in temperatures.

but what does the owners manual tells you to use?

 

[simple_gifts]

I have found that cheap oil that really isn't for use in the vehicles I own should just be passed over. JMO.

My 19 qts of 20W-50 GTX I got for free didn't end up in any of my vehicles, summer or winter.

 

[OneEyeJack]

Is oil such an expensive part of your maintenance expenses that you have to resort to something like this? Following the manufacturer's recommendations is easy.

 

[SwampSurvivor]

It won't help any ... but it won't hurt any. The Duratec V6 engines were pretty well designed, and certainly had being run hard considered during the design process.

I'd run a good 5w-30 in it and call it a day.

It has 300K KM on it - whatever got it to 300K KM will work just fine.

 

[CATERHAM]

Originally Posted By: Miller88
It won't help any ... but it won't hurt any.

Unless the OP is seeing very high oil temp's (very unlikely) running the 50wt oil without thinning it out will be seriously counter-productive, not just in fuel economy but in potentially increased engine wear.

 

[901Memphis]

Don't run it straight into the engine as a 50 weight but rather blend it with any 20 weight to get it closer to what your engine needs. This way you can get rid of it but no stress your oiling components. I'd blend it in equal ratio with a 5w20 or 3:2 ratio of 20:50.

 

[Whimsey]

Around 1 year after I purchased my 1996 Zetec Contour new I went from Mobil 5W-30 to Castrol Syntec 5W-50. After all "thickerer is betterer"

. It ran without real problems. Cold weather starts were a bit slower and noisier. But I really noticed that the Zetec lost it's Zip and felt lethargic. Plus my gas mileage went down a lot. After a few years I went back to 5W-30 grade and my engine felt much peppier and my gas mileage went up substantially. With the 5W-50 I would get usually 26 mpg, with the 5W-30 I get 35+ mpg, this is on the highway.

Whimsey

 

[tmrmathias]

Okey, thanks for the replies. 5w-30 of some good quality oil it is then.

I wouldnt have asked this question if the price difference between 5w-50 & 5w-30 were almost 60 dollars, but it is..
5w-50 for around 45$, 5w-30 for 100 $.

Welcome to sweden, the land of a tousand taxes!

 

[Clevy]

Originally Posted By: Whimsey
Around 1 year after I purchased my 1996 Zetec Contour new I went from Mobil 5W-30 to Castrol Syntec 5W-50. After all "thickerer is betterer"

. It ran without real problems. Cold weather starts were a bit slower and noisier. But I really noticed that the Zetec lost it's Zip and felt lethargic. Plus my gas mileage went down a lot. After a few years I went back to 5W-30 grade and my engine felt much peppier and my gas mileage went up substantially. With the 5W-50 I would get usually 26 mpg, with the 5W-30 I get 35+ mpg, this is on the highway.

Whimsey
grades.


Wow. 9mpg different with just a grade switch. There has to be more. I know that the engine will have less pumping losses and such but 25+%.
That's awesome.

 

[Whimsey]

Originally Posted By: Clevy
Originally Posted By: Whimsey
Around 1 year after I purchased my 1996 Zetec Contour new I went from Mobil 5W-30 to Castrol Syntec 5W-50. After all "thickerer is betterer"

. It ran without real problems. Cold weather starts were a bit slower and noisier. But I really noticed that the Zetec lost it's Zip and felt lethargic. Plus my gas mileage went down a lot. After a few years I went back to 5W-30 grade and my engine felt much peppier and my gas mileage went up substantially. With the 5W-50 I would get usually 26 mpg, with the 5W-30 I get 35+ mpg, this is on the highway.

Whimsey
grades.


Wow. 9mpg different with just a grade switch. There has to be more. I know that the engine will have less pumping losses and such but 25+%.
That's awesome.


Yes, it was a lot and even surprised me some what. No mechanical problems just the oil change to 5W-50. As I said it felt sluggish with the 5W-50. Maybe a small 4 cyl double overhead cam (?) engine spec'd for 5W-30 is more susceptible to much heavy weight oils affecting it's economy

.

Whimsey

 

[Leo]

From reviewing literature, each grade is worth anywhere from 0.5-2% in fuel economy between them. So I would reasonably expect a 3-5% drop in fuel economy between a 30wt and 50wt.