10-30W versus 10-40W

[Doc_Bob]

I have a Honda powered power washer (air cooled engine) and the owners manual states 10-30W or 30W oil for the engine. I have a couple of cases of 10-40W pennzoil. Can I use the 10-40W pennzoil instead of 10-30W oil?????
Bob

 

[Doc_Bob]

"Singlegrade oils will become obsolete for performance engines in the future. We dropped SAE 30 and SAE 40 because SAE 10W40 does everything 30 or 40 can doé*�nd some things the straight grades can't do様ike increasing horsepower. If an off-roader doesn't like 10W40, then use 20W50. It can do everything a 10W40 can do except pass the sub-zero viscosity test at -20 degrees C."

Oil Viscosity

I still don't k now the answer to my question. Just thought i would post this anyway.
Bob

 

[Doc_Bob]

"SAE 30 is SAE 30 no matter what the "W" prefix number is: 0W, 5W or 10W. This viscosity in centistokes (cSt) @ 100 degrees C is with the minimum of 9.3 cSt and a maximum of 12.5 cSt.

"SAE 40 is SAE 40 no matter what the "W" prefix number is: 5W, 10W, 15W or 20W. The viscosity @ 100 degrees C is within the minim of 12.5 cSt and a maximum of 16.3 cSt.

"SAE 50 is SAE 50 no matter what the "W" prefix number is: 5W, 10W, 15W or 25W. The viscosity @ 100 degrees C is within the minimum of 16.3 cSt and a maximum of 21.9 cSt.

So cSt is the "key".

30 weight has min 9.3 and max 12.5 at 100 degrees C

40 weight has min 12.5 and max 16.3 cSt at 100 degrees C.

So, technically, 40 W can fall in the range for 30W at 100 degrees C. with a cSt 12.5.

 

[Wayne County Hose]

Bob,

I do not know the answer to your question. However, I will offer this. If you are going to talk to yourself, you should do so under different screen names. It really doesn't look good. I do talk to myself too, I even argue with myself, but I follow 2 rules. 1. Don't do so when there's witnesses. 2. If you argue with yourself, you better not lose!

Andy.

 

[MrJimi]

Andy, that was real funny
I have an older PW and it says to use a 30 weight not a mixed weight, there is a difference in the oil big time. You may have a newer one than mine
good luck and carry on with your conversation, sorry to have interrupted you

 

[RWEST]

If you are going to talk to yourself, you should do so under different screen names. It really doesn't look good. I do talk to myself too, I even argue with myself, but I follow 2 rules. 1. Don't do so when there's witnesses. 2. If you argue with yourself, you better not lose!

ROFL!!! That's funny!!

 

[Red55]

Bob and everyone else ya a riot! BUT if you think you're talking to yourself now wait until you're having problems because you didn't spring for 10w30 OIL! Buy the right stuff JMHO -Ed

 

[3RRL]

Yeah, that was a great reply Andy!
I agree, why not get what your engine calls for? It can't take that much oil and it leaves the other stuff for your other engine or whatever you bought all the 10w40 for.

 

[RalphVa]

The 10w40 will work fine. At startup, it'll work like a 10w and is approved (e.g. 10w30). At operating temperature, it'll be slightly more viscous than a 10w30 or 30w. You won't notice any difference in performance.

Ralph

 

[Doc_Bob]

I enjoyed the conversation, I knew exactly what I was going to say and I agreed with every word!
Bob