Blend and Full Synth

[RobertClarke6666]

My car take 4.2 qts of 5W30. I have 4 Qts of Motorcraft Synth
Blend and 1 quart of Castrol Synthetic. Can I use the 4 qts of
Blend and put in the 6 or so ounces of Full Synth? Thank you

 

[Silber Igel]

Yes! But I'd fill with 4qts; run the motor; let it sit 10 minutes; check to see if you need those 6 0z. As long as you are in the 'zone' between full and addaquart you really wouldn't need to fuss with it.

 

[CourierDriver]

see below

 

[daves87rs]

Why not?

 

[salesrep]

Yes.

 

[PT1]

Yes, won't hurt anything

 

[FL_Rob]

You guys might yell at me but one time I had a mix of about 4 different brands and weights,(partials)I wanted to use them all up,so I did,all in one change.It probably ended up with a 7w32 or something like that, I never noticed a difference in anything.

 

[crazyoildude]

maybe thats why your engine uses oil
Seriously mixing most oils wont hurt but its better to stick with one

 

[KW]

Go for it.

 

[ThirdeYe]

Is the extra 6 oz. really necessary? Chances are 4 quarts should put it very close to the full mark if not exactly on it. My car calls for 4 quarts and putting in 4 quarts puts it a little bit over the full mark. Most cars I've maintained are that way.