What does a single grade oil translate to exactly?

[Zaedock]

I picked up a bunch of Chevron Delo 400 SAE30 a few years ago for $.99/gal and it works great in my Jeeps. The 12.1cSt @100C viscosity is perfect and the sheer stability when I'm buzzing my 2.5L trail rig in low range is piece of mind.

I haven't researched other brands of SAE30, but the Delo has a decent pour point of -24*F. I have used it down to 40*F and could see it easily flowing from the rockers on a cold start. The idea that you have to use it above 60 or 70 degrees F seems absurd to me.

I don't remember who calculated these figures (maybe Audi Junkie?), but here is the viscosity of Chevron Delo 400 SAE30 at the listed temp.

Delo SAE 30
40c 105 cSt
10c(50f): 726.5 cSt
5c(41f): 1102.3
0c(32f): 1731
-5c(23f): 2825.4
-10c(14f): 4809.1
-15c(5f): 8575.7
-20c(-4f): 16100.7


I have no idea why many here are afraid to use single weight oils. With the deal I had on a $.99/gal HDEO, an 8-10K mile oil change costs me about $4.00.

 

[edhackett]

The Rotella SAE 30 has a pour point of -18C or 0F. As addyguy said, it's probably save down to about 32F. I think the common recommendation for SAE 30 is above 50F.

Ed

 

[Gary in Sandy Eggo]

Originally Posted By: edhackett
I think the common recommendation for SAE 30 is above 50F.Ed

I had a couple 1990's cars that specified 5w30 oil, but said SAE-30 was OK down to 40F if a multi-grade were not available. I ran SAE-30 in them during the summer when overnight garaged temps never went below 55F and daytime temps could be anywhere from 70F-95F. Oil consumption with mono-grade was 20 percent of that with multi-grade oils.

 

[Steve S]

Originally Posted By: PandaBear
But why, when multi-visc oil that meets the latest spec with additives last longer and performs better, at the same/similar price? Even lawn mower deserves multi-visc oil.
My lawn mower deserves any oil that is left over in the shop.

 

[Dieselbob]

My $8000.00 Grasshopper 618 runs on YB Pennzoil 30w. (I put YB 5W20 in during the winter simply to move it in and out of my unheated storage building), as does my 1967 Bolens 1050,(as old as I am with the original Wisconsin engine), my 1989 Bolens 1467,(almost 2000 hours on engine), and my 1995 MTD pushmower. Still use a LOT of 30w at my house.

 

[zrxkawboy]

I wouldn't hesitate to use SAE 30 above freezing.

 

[Doug Hillary]

Hi,
zoomzoomix - Single grade engine lubricanst perform extremely well in the correct application and against the prevailing ambient temperature range

In one very sophisticated V8 engine I am aware of SAE30 is approved for all summer temperatures. SAE20 is required for winter temperatures below +5C

Single grade lubricants are often used selectively in high speed heavy diesel engines

 

[kingrob]

I always have some straight 30 wt laying around. I use it in lawnmowers, yes, but I do have some older cars that call for it. My Cadillac calls for (in my region) straight 30 in winter, and 40 or 50 wt in the summer. Seeing as it's got close to 37 years on the same engine and transmission, I don't mess with the formula too much. I just can't find straight 50 anymore so it gets 20w50 in the summer.

The only straight 30 wt I would avoid would be ND. What, may I ask, do they use non-detergent oil for in this day and age?

 

[Dieselbob]

My shop air compressor specifies ND 30W, and the PTO driven bulk product blowers, (resemble big shaft driven Roots superchargers)on some of my employer's semis also require ND 30W for the gear cases.

 

[adibigs]

my snowthrower manuals says to use a high quality detergent oil sae 30

 

[rdharper]

Originally Posted By: zoomzoomlx


The oil in question here is straight 30 weight Rotella. I picked up a huge bunch from Advance Auto yesterday. I live in southeast PA where it doesn't get arctic cold in the winter. Car in question is a 93 Escort which calls for 5w30. I was just curious if it was okay to run the 30 weight for winter use in the future or if not, i'll just keep it for the warmer 8-9 months of the year.


Perfectly safe way to use an excellent oil.

A few facts. The second number in the 5w30 is the weight the oil is intended to settle to. The first number in a multi-weight oil is intended to be the starting weight in a cold engine under a normalized cold environment.

Note that race cars, F1, Nascar etc, do not use multi-weight oil, as it will not take the sheer forces that a single weight will, as stated by others earlier. Once you get the engine warmed up, the only thing that matters is the second number, which is the same as your single weight.

That having been said, 90% of engine wear occurs in the first few minutes of starting a cold engine. So the thinner that first number is, the better. This is why modern engines are shipped with 0w20. 0 for safer warmup, 20 for fuel consumption in a tight engine.

So it's a judgement call, which is why everyone has an opinion.

All things considered, the age of your vehicle, the way you intend to use it, you are perfectly safe.

There is a another whole discussion on whether you should use a thicker oil as the engine starts to blow-by. Personally, I'd stick with the 30w and add oil as necessary, as oil is cheap. Thickening the oil, going to a higher weight, will stop oil consumption, but can provide less protection to crank bearings, for instance. When the blow-by gets bad enough, replace the rings if you like the vehicle.

 

[BuickGN]

Originally Posted By: lexus114
Originally Posted By: 02zx9r
Straight 30 weight is going to be far more shear stable than multi-vis 5W or 10W30

I would use straight weight in warm temps and cool (not cold) but 60F and up.

Straight 40 weight in a bike will perform better than 10W40


I agree with you on the 60F and above.but not necessary in a newer vehicle.That`s just my opinion.(and I`m not alway`s right)


I've been using a synthetic straight 30wt in my TL from a very early age. I probably wouldn't use a dino 30wt but synthetic acts like a 10-30 anyway. For my application, lots of freeway miles and few cold starts, it's very well suited.

It's been used the in the GF's Murano also since the 7,000 mile mark. Oil pressure is pretty much instantaneous on a 40 degree cold start.

 

[Volvohead]

Originally Posted By: zoomzoomlx


The oil in question here is straight 30 weight Rotella. I picked up a huge bunch from Advance Auto yesterday. I live in southeast PA where it doesn't get arctic cold in the winter. Car in question is a 93 Escort which calls for 5w30. I was just curious if it was okay to run the 30 weight for winter use in the future or if not, i'll just keep it for the warmer 8-9 months of the year.


I live pretty near to you. Straight 30 come February and March in central Bucks is going to be a bear to crank in a '93 Escort. What you save on oil you'll spend on batteries. It hits single digits. I would use it only between late April and early October. Run a 5w30 during the cold months.

The Rotella single vis is a fine summer oil that is very shear resistant. Good stuff.

 

[zoomzoomlx]

I'll save the 30 weight for the warmer months then. I just put in 10w30 Rotella last week and i'll see how that does. I'm going to see if I can run this interval until April. Think its too long on dino oil?

 

[Whimsey]

Wow! The last time I used straight weight oils was in my purchased new 1972 VW Beetle. 20W for winter and 30w for the rest of the year. I lived in central NJ and even their winter temps "challenged" winter starting on 20W straight oil.

Whimsey

 

[TallPaul]

Originally Posted By: Whimsey
I lived in central NJ and even their winter temps "challenged" winter starting on 20W straight oil.
Of course the 20w in that day was no comparison to the 20w of today, at least the (now apparently discontinued

) Valvoline Premium Conventional 20w, which G-Man ran all winter and appeared to be essentially a 10w20, probably because of the high quality modern base oils used.