5w30 vs 10w30

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If temps are above freezing could 10w30 offer more cold start protection than 5w30 in a vehicle that calls for 5w30? What temps would make 5w the better choice?
 
they're both still a 30 weight, and 5wXX will flow more quickly. I'd go with quicker lubrication vs. thicker anytime.

That said, in KY you can likely use 10W30 year round if your vehicles are garaged.
 
There would be no difference between the two around 32°F or above. Zero difference. At say -15°F the 5w would have an advantage for sure. The test for CCS and MRV for 10w is at -25°C or -13°F. So at -15°F a 10w would be able to work. Though the 5w would be better given it's tested at -30°C for CCS and tested at -35°C for MRV.
 
No. Not at all. A 5w would flow better than a 10w unless it was very, very cold outside. Like -15°F or colder.
 
Check out the NOACK numbers on 10w30 they are usually lower than 5w30, In your part of the country this could result in less varnish and deposits in the intake tract. 5w30 will have no benefits over it.
 
Trav the funny thing I noticed with the PQIA test results for 10w30 showed that Warren Oil 10w30 had the best NOACK at 7.6. All of the others were above 10 up to 13. So a oil made by Warren Oil beat Havoline and the others.

I hope your eyes are doing ok. Take care of yourself.
 
5w30 is going to flow much better at very cold temps -10, -20 and below,but lots of older vehicles used to use 10w30 and 10w40 and still start in -20, and even -30 temps. I grew up in North Dakota ..Fargo and back in 60's and 70's my dad started the big V8 F150 and our ford Galaxy many times in temps well below -20 with a few -30 temps tossed in with 10w40 in the sump. Of course he did use a battery heater and sometimes just a small shot of starting fluid , but they always started.

Now many newer vehicles of today use 0w20 which can go to even lower temps. I think that 0w20 is probably found only in synthetic or semi synthetic though. Anything colder than -30 and I am staying home.
 
Originally Posted By: Spitter
A full syn 10w would flow better than a 5w conventional correct?

And it’s not about flow, it’s about pumpability. Both the synthetic and the conventional will pump down to the limit of pumpabilty for whatever the W rating happens to be, they both have to meet the same spec.
 
As long as the temperature is above the minimum pump ability limits of each oil. both oils will lubricate and circulate at the same speed. There is no difference. No additional protection from thinner, nothing. Pumpable is pumpable.
This myth of faster circulation is false.
 
Some may argue as follow:

Doesn't 10W30 have less vii and possibly lower Noack?

Didn't we also have a recent thread about xWy and selecting lowest (y-x) that meets the spec.
Meaning to select the highest x that meets your W.

Therefore 10W-30 over 5W-30 if 10W meets your winter temp. requirements.

some may argue that we maybe splitting hairs ...

Having said that, I am 1000 miles into M1 EP 10W-30 and I like it VERY much! In winter i was using PPPP 5W30.
 
Originally Posted By: OilUzer
Some may argue as follow:

Doesn't 10W30 have less vii and possibly lower Noack?

Didn't we also have a recent thread about xWy and selecting lowest (y-x) that meets the spec.
Meaning to select the highest x that meets your W.

Therefore 10W-30 over 5W-30 if 10W meets your winter temp. requirements.

some may argue that we maybe splitting hairs ...

Having said that, I am 1000 miles into M1 EP 10W-30 and I like it VERY much! In winter i was using PPPP 5W30.





Yep, several threads on that lately. What's your vehicle spc'd for in the manual?

I'll be going 5w30, and once used up maybe 10w30 in the 4Runner which is spec'd 0w20 for CAFE.
 
Originally Posted By: JLTD
... What's your vehicle spc'd for in the manual?

I'll be going 5w30, and once used up maybe 10w30 in the 4Runner which is spec'd 0w20 for CAFE


Spec for this car is 5W-20 (recommended) or 5W-30 or 10W-30 and there is temp chart to select either 5W or 10W ...

I have never used 5W-20 and can use either 5W or 10W all year! They both meet the W spec in my area BUT I like to split hairs ... lol
 
thumbsup2.gif
Thanks--
 
*I calculated there is very little difference between the two until you get down to 26 degrees F. then the 5W definitely starts to separate itself from the 10W .
Originally Posted By: Spitter
If temps are above freezing could 10w30 offer more cold start protection than 5w30 in a vehicle that calls for 5w30? What temps would make 5w the better choice?
 
Originally Posted By: ChrisD46
*I calculated there is very little difference between the two until you get down to 26 degrees F. then the 5W definitely starts to separate itself from the 10W .
Originally Posted By: Spitter
If temps are above freezing could 10w30 offer more cold start protection than 5w30 in a vehicle that calls for 5w30? What temps would make 5w the better choice?
I've used Delo 15w-30 in single digits F. I didn't notice anything out of the ordinary.
 
Originally Posted By: Spitter
If temps are above freezing could 10w30 offer more cold start protection than 5w30 in a vehicle that calls for 5w30? What temps would make 5w the better choice?


All of my car/truck manuals that have an ambient selection chart says that 10w-30 can be used down to 0F. Most BITOG members agree that it's ok down to -15F.
 
Not sure what part of KY you are in but I'd bet 10w would be just fine. I would guess your climate is similar to the one I live in along the VA/NC border. I used to run 10w-30 in a 2001 4Runner year round with no problems.
 
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