Which major 5w30 Syn...is the thinnest ?

[Oregoonian]

Now that my 03' Focus is over a 100K....I'm thinking of moving to a thin 5w30 syn (or blend).

Can some of you expert BITOG people tell me which major 5w30 synthetic (or blend)) is the thinnest....and provide some evidence. Also....tell me if you think this is a good idea.....or should I just stay with a 5w20 ?

Would appreciate any and all comments.

 

[CATERHAM]

They are all pretty much the same with a HTHSV of around 3.1cP and a VI in the 170 area.
Why do you want to use a heavier than 20wt oil, particularly in the winter?

 

[Lead Shoes]

Mobil 1 0w30 is one of the thinnest 30 weight oils you can find on most shelves.

I don't know what has you thinking you need to move up a weight, 5w20 is proven time and time again to produce nearly the same wear numbers as 30 weight for the normal driver. If I was you I would stay using 5w20.

 

[OldCowboy]

I know of NO reputable study that shows SM/SN 30 weight oils give better protection in engines which spec a SM/SN 20 weight.

 

[chubbs1]

Originally Posted By: OldCowboy
I know of NO reputable study that shows SM/SN 30 weight oils give better protection in engines which spec a SM/SN 20 weight.



Old Cowboy is right, Some engines that spec 5w30 should probably spec a higher grade oil IMO because some of them shear the 5w30 shortly after normal driving. Therefore, in most engines, I would use either a 0w30 and forget about it or a high quality 5w20. the differences will be negligible.

Keep in mind also most CONVENTIONAL 5w20's are made of better base stocks than 5w30. Just look at the spec's.

 

[chad8]

only use 30 wt if you are starting to burn some oil. 5w20 pp is decent oil.The Focus i see like motorcraft 5w20 semi for a cheaper option with a motorcraft (puro) filter.. I do see you adding too much mmo . Not needed every tank plus redline sl-1 is more than sufficient. Not sure why you would use either except about every 3000-5000 miles for intake and valve cleanup which on a focus is not really necessary. this is a very clean running efficient motor. Ford had done a great job with it.

 

[Nick R]

Just stick with the 5W-20, no reason not to.

 

[SLCraig]

I'd just stick with what's working.
Although I wouldn't not use 5w30 in your car if you have some old stash to use or something. I have one more jug of 5w30 which I'll use in my Honda this summer. But back to 5w20 for the rest of the OCI's after that.

 

[Oregoonian]

Thanks for all your opinions....based on the info you provided...I'll continue to use a Xw20 oil.

I have a jug of Mobil 1 0w20 in my stash.....so that will be my next oil change.

 

[jorton]

Castrol Syntec and Edge are thinnest 5w30.

 

[TFB1]

Jumping up a couple cSt isn't going to make a noticeable change in operation or fuel milage...

 

[mshu7]

Excellent choice on the Mobil 1 0w20.

 

[CATERHAM]

Originally Posted By: jorton
Castrol Syntec and Edge are thinnest 5w30.

You can't rely on the KV100 spec's of different oils to determine which is thinner. Unless you know the HTHSV of these oils you really don't know.

 

[garlicbreadman]

using any 5w30 isnt going to hurt anything...

 

[mechtech2]

That Zetec engine in the Focus was once spec'd for 5-30 [now 5-20].
No changes were made to it.
Anybody's 5-30 will be just great.
No need to seek out a thin one. And a thicker one may shear thinner, anyways.

 

[Whimsey]

Originally Posted By: mechtech2
That Zetec engine in the Focus was once spec'd for 5-30 [now 5-20].
No changes were made to it.
Anybody's 5-30 will be just great.
No need to seek out a thin one. And a thicker one may shear thinner, anyways.


The OP says his Focus has the 2.3L Duratec, not the Zetec 2.0 as I have in my 1996 Contour. I think the 2003 2.3 Duratec engine was factory spec'd for 5W-20. When Ford started to back spec older engines to 5W-20 they held back on the Zetec, reasons unknown, for several years. I still run 5w30 synthetic or synblends. I get 26+ mpg locally and 35+ mpg on the highway at 75 to 80 mph, albeit vacation driving in warmer months for the highway mpg.

Whimsey

 

[Oregoonian]

Originally Posted By: mechtech2
That Zetec engine in the Focus was once spec'd for 5-30 [now 5-20].
No changes were made to it.
Anybody's 5-30 will be just great.
No need to seek out a thin one. And a thicker one may shear thinner, anyways.


My 03' Focus engine is not a Zetec.....it a 2.3L Duratec (see below).