HD30 Castrol motor oil - can I use one quart along with 5 quarts of 5W20?

[SegunDunt]

I accidentally picked up a quart of HD30 motor oil along with a 5 quart jug of 5W20 -- both are Castrol. Problem is I did this while on a road trip and I'm unable to return the quart to the store and exchange it for 5W20.

So my question is, can I combine 5 quarts of 5W20 with a quart of HD30 or should I just pick up a quart of 5W20? Since I won't be replacing the oil filter this time around I may not even need a lot of the HD30, but I wouldn't want to jeopardize the motor by adding any amount of heavy duty oil if there is potential for problems.

Thanks for your help.

 

[swshawaii]

4.6L V8 capacity WITH filter is 6 quarts. 4.0L V6 is 5 quarts.
Which engine? Also seems wasteful NOT to change the filter.

 

[MustangP51]

My recommendation would be No. Buy the 5w-20

 

[SegunDunt]

4.6L V8 capacity WITH filter is 6 quarts. 4.0L V6 is 5 quarts.
Which engine? Also seems wasteful NOT to change the filter.

Yup, I've got the V8, but I don't need to replace the filter so I'll likely only use 5.5 quarts of new oil, if that. I replaced the filter 2 weeks ago and have since had hit the highway for a road trip. Truth be told I don't even need to do an oil change for another 1k but I'd rather run new oil to remove any deposits that may have come unstuck from a non-stop 2k drive. I figure the filter is good for another 3k.

Anyhow, if there isn't much enthusiasm for mixing oils I guess I won't do it.

 

[colintrax]

I'd just throw the bolt back in when the oil starts to slowly come out, then add the 5 quarts. The .25quarts you'll be low is fine, your engine will never know.

 

[budwich]

I doubt adding a small amount of any oil of different weight will cause much problem although depending on where you are "wintering", the heavier straight weight might be an issue in the "dead of winter". If you are lucky to live in the "warmth of the sun" all year round, well... can you say "non-issue".

 

[colintrax]

^ HD30 is more of a lawn mower oil, its not multi viscosity so I would worry about whether or not it will mix with the other oil.
Better off being a lil low

 

[Carguy3J]

Other then slightly changing the viscosity when cold, no, mixing 1 quart of the HD30, with 5 quarts of 5w20 shouldn't really matter.

However, your wasting your time and money changing it to begin with. Unless you have some other good reason/justification for changing it (new/freshly rebuilt motor, or some sort of problem that would contaminate the oil so quickly, such as it running way too rich), there is no reason to change it just because you went on 2,000 mile trip. If anything, a long highway drive is less likely to degrage the oil, as opposed to accumulating the same miles over a longer period of daily stop and go type driving.

Under normal circumstances, with synthetic oil (which you should use), oil change intervals of 5,000-7,500 miles are perfectly fine. Also, if its time to change the oil, its time to change the filter.

 

[SegunDunt]

Thanks for the responses, everyone.

I use regular 5W20, haven't yet used synthetic but now that I'm at 100k I may opt to switch.

 

[colintrax]

Haha you shoulda switched a long time ago

 

[JohnnyO]

You can add the 30 wt. It won't hurt anything.
That being said, driving 2000 miles is no reason to change fresh oil. Even conventional oil is good for 5000 miles. Just change the oil and filter whenever it is due and save the 30 wt for your lawnmower.