a bit confused about straight 30 weights

[BrotherMichigan]

Originally Posted By: TWG1572
Originally Posted By: bmwpowere36m3
SAE 30 is straight 30-weight or basestock. xxW-30 oils start with "lighter" weight basestocks and have viscosity modifiers so the oil "thins" down similar to a 30W oil at operating temps...


Did you mean thin or thicken? I'll agree that you start with the lighter base stock, but I always thought the viscosity modifiers thickened the oil as temperature increases. The oil thickens to a 30wt.


A 30wt is thinner at operating temp than an 10wt at ambient temp, so it does thin as the temperature increases, just not as much as a straight 10wt would. The viscosity modifiers only thicken the oil compared to the viscosity of the lighter weight oil at operating temp.

 

[TWG1572]

Originally Posted By: BrotherMichigan


A 30wt is thinner at operating temp than an 10wt at ambient temp, so it does thin as the temperature increases, just not as much as a straight 10wt would. The viscosity modifiers only thicken the oil compared to the viscosity of the lighter weight oil at operating temp.


Gotcha. Thanks!

 

[Merkava_4]

Originally Posted By: bubbatime
There are only a few engine manufactures. Briggs, Kawasaki, Kohler, Honda are the bulk of what most people would work on. I know exactly what the engine manufacturer recommends.


They have changed their viscosity recommendations throughout the years. You won't know exactly which viscosity to use unless you consult the owners manual for the corresponding engine you're working on. Over the years, Briggs & Stratton has recommended HD30, 10w30, and even 5w30 at times; sometimes even full synthetic. HD30 is a good universal grade, but if you want to be a hardcore by-the-book professional, you'll put in the grade that the manufacturer specifies for that specific model of engine you have sitting on the bench.

 

[Merkava_4]

Originally Posted By: mech_tech
I have no problem running supertech 30 HD, the problem I do have is finding an oil with the detergents of the oem oil.


I have always assumed that HD30 oils (that are not non-detergent) have the same level of detergents in them as their multi-viscosity counterparts. The only difference being is that the HD30 oil is not loaded up with viscosity index improvers. That's what I've always assumed and will continue to assume that until somebody corrects me.

 

[mech_tech]

If I remember correctly, the valvoline 10w30 I currently have in a 11 hp honda has a calcium level of just over 700...where as the briggs sae30 supposedly has around 2200. There is not much VOA information on straight weight oils from what little I have found. As for how I learned Pinnacle makes the briggs oil, I had e-mailed briggs tech support with basically the same questions I asked here, and all I got was a very uninformative MSDS sheet for their oil. To say the least, I believe this website gave me a bit more information!!!!

 

[doitmyself]

If you are a stickler about using a true SJ rated HDEO oil in your mower, Chevron DELO 400 30 wt. is still available:
https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=77118&docFormat=PDF

 

[HangFire]

Originally Posted By: Merkava_4
Originally Posted By: mech_tech
I have no problem running supertech 30 HD, the problem I do have is finding an oil with the detergents of the oem oil.


I have always assumed that HD30 oils (that are not non-detergent) have the same level of detergents in them as their multi-viscosity counterparts. The only difference being is that the HD30 oil is not loaded up with viscosity index improvers. That's what I've always assumed and will continue to assume that until somebody corrects me.


That is my understanding as well.

 

[philipp10]

Originally Posted By: mech_tech
I have no problem running supertech 30 HD, the problem I do have is finding an oil with the detergents of the oem oil. Do you guys ever add any detergent to the oil in certain situations for normal running? As I stated previously, the oils I have tried just don't seem to get as dirty and dark as the briggs oil did, but surely there must be something equal to that on the market. I did find out that the current briggs conventional 30 weight is made by Pinnacle, but I have never seen their brand anywhere before. Has anyone else ever noticed that the oil changes on small engines tend to remain cleaner when using off the shelf passenger car oils??? I suppose it's part of being a mechanic, but when I feel there is something I am overlooking, I can't help but over analyze the problem and find out as much as I can...not to mention these little engines when new are getting ridiculously priced, so I want to make them last.


You are making the assumption that because the Briggs oil came out dirty that it must have more detergent. Is it possible that the Briggs oil was the factory fill that came with the mower and that you used that as it's first oil....during breakin? And that maybe the rings were not even seated yet...hence the cause of your dirty oil? IMO, your making a huge mountain out os a molehill. There was an earlier post from a guy that never changes his mower oil for years and years. This is a non-issue.

 

[TFB1]

Originally Posted By: philipp10

You are making the assumption that because the Briggs oil came out dirty that it must have more detergent. Is it possible that the Briggs oil was the factory fill that came with the mower and that you used that as it's first oil....during breakin? And that maybe the rings were not even seated yet...hence the cause of your dirty oil? IMO, your making a huge mountain out os a molehill. There was an earlier post from a guy that never changes his mower oil for years and years. This is a non-issue.


Agreed... Besides Briggs is now recommending to add only, oil never needs changing...

 

[mech_tech]

Well then I suppose Rotella T5 it is for the engines with hydraulic lifters, and supertech 30HD for the flat tappets. One last question since we on the subject, why would briggs recommend a multi-viscosity oil when using synthetic, but a straight grade when using conventional? I see straight weight synthetics are available such as Royal Purple, so they are made and out there...but what characteristic of the synthetic makes the multi-viscosity a better choice? The v-12 and v-16 engines I work on only use conventional 40w low ash oils, so the topic of synthetics never comes up in our factory classes. Thanks again for the advice fellas!!!

 

[bmwpowere36m3]

Originally Posted By: BrotherMichigan
Originally Posted By: TWG1572
Originally Posted By: bmwpowere36m3
SAE 30 is straight 30-weight or basestock. xxW-30 oils start with "lighter" weight basestocks and have viscosity modifiers so the oil "thins" down similar to a 30W oil at operating temps...


Did you mean thin or thicken? I'll agree that you start with the lighter base stock, but I always thought the viscosity modifiers thickened the oil as temperature increases. The oil thickens to a 30wt.


A 30wt is thinner at operating temp than an 10wt at ambient temp, so it does thin as the temperature increases, just not as much as a straight 10wt would. The viscosity modifiers only thicken the oil compared to the viscosity of the lighter weight oil at operating temp.


+1

Any oil, regardless of weight thins down as its temperature increases. So for example, take this imaginary "thickness scale" of 0-10 ("1" being very thin and "10" very thick)

SAE 30 would be 6 when cold and 3 when hot
10W-30 would be 5 when cold and 3 when hot
5w30 would be 4 when cold and 3 when hot

Made up, numbers of course... but should make the point

 

[TFB1]

Originally Posted By: mech_tech
Well then I suppose Rotella T5 it is for the engines with hydraulic lifters, and supertech 30HD for the flat tappets. One last question since we on the subject, why would briggs recommend a multi-viscosity oil when using synthetic, but a straight grade when using conventional? I see straight weight synthetics are available such as Royal Purple, so they are made and out there...but what characteristic of the synthetic makes the multi-viscosity a better choice? The v-12 and v-16 engines I work on only use conventional 40w low ash oils, so the topic of synthetics never comes up in our factory classes. Thanks again for the advice fellas!!!


Weather the engine has hydraulic or solid lifters is of no consequence, high spring pressure on a flat tappet cam dictates amount of zinc necessary in oils(why for most part roller cams are used these days)... Pressures in OPE are minuscule compared even the most mundane automotive engine...

 

[Merkava_4]

Originally Posted By: mech_tech
One last question since we on the subject, why would briggs recommend a multi-viscosity oil when using synthetic, but a straight grade when using conventional?


They probably figure the synthetic won't sheer as much; that's especially important when running 5w30.
10W-30 conventional stays in grade pretty good but that 5w30 conventional always sheers down.

 

[bubbatime]

Originally Posted By: mech_tech
One last question since we on the subject, why would briggs recommend a multi-viscosity oil when using synthetic, but a straight grade when using conventional? I see straight weight synthetics are available such as Royal Purple, so they are made and out there...but what characteristic of the synthetic makes the multi-viscosity a better choice?


It has been said on this very sight that it would be nearly impossible to actually make just a synthetic SAE30 oil. Synthetic oil has very good cold follow properties as well as offering excellent protection in extreme heat. So the SAE30 labeled oil that Royal Purple and Amsoil sell are actually mislabeled products. Meaning, for marketing purposes, they are sold as SAE30 weight oils, but if you sent them to a lab they would actually test as 5W30 or 10W30 synthetic oils. So in a round about way, they are almost identical to any other 5W30 or 10W30 synthetic oil sold by other manufacturers. It's just marketing, plain and simple.

Your typical 5W30 synthetic oil is actually a very robust product. For instance, on the Corvette, they found that the oil temperatures were very high when the car was ran on a track. The engineers advised that an oil cooler needed to be installed on the car. The penny pinchers got involved, and it was decided that instead of installing oil coolers on every Corvette sold, they would specify synthetic 5W30 Mobil 1 oil instead. And this "thin oil" performs pretty darn good at those extreme track temps, they have found.

 

[kschachn]

Originally Posted By: Merkava_4
They probably figure the synthetic won't sheer as much; that's especially important when running 5w30. 10w30 conventional stays in grade pretty good but that 5w30 conventional always sheers down.


Shears. Sheers are what are on windows.

 

[racer12306]

Originally Posted By: bubbatime
Originally Posted By: Merkava_4
He'd have to have the corresponding owners manual to every single model number if he was gonna do that.


There are only a few engine manufactures. Briggs, Kawasaki, Kohler, Honda are the bulk of what most people would work on. I know exactly what the engine manufacturer recommends. Don't care what the equipment manufacturer recommends, if they deviate from the engine manufacturers recommendations. Pretty simple to memorize...


It's also amazing what Google can locate for you.

 

[HangFire]

Originally Posted By: bubbatime

Your typical 5W30 synthetic oil is actually a very robust product. For instance, on the Corvette, they found that the oil temperatures were very high when the car was ran on a track. The engineers advised that an oil cooler needed to be installed on the car. The penny pinchers got involved, and it was decided that instead of installing oil coolers on every Corvette sold, they would specify synthetic 5W30 Mobil 1 oil instead. And this "thin oil" performs pretty darn good at those extreme track temps, they have found.


Yes, the new Vette performs so well the car goes into limp home mode due to heat after 1-2 laps around the track.

http://driveviper.com/forums/threads/8662-Be-careful-when-tracking-with-the-new-Corvette-C7-Z06

http://gmauthority.com/blog/2015/07/yet-another-c7-corvette-z06-engine-bites-the-dust/

 

[Merkava_4]

Originally Posted By: kschachn
Shears. Sheers are what are on windows.


If that's the only thing you can find to criticize me about, I'm doing good.

 

[NH73]

Originally Posted By: bubbatime
Originally Posted By: mech_tech
One last question since we on the subject, why would briggs recommend a multi-viscosity oil when using synthetic, but a straight grade when using conventional? I see straight weight synthetics are available such as Royal Purple, so they are made and out there...but what characteristic of the synthetic makes the multi-viscosity a better choice?


It has been said on this very sight that it would be nearly impossible to actually make just a synthetic SAE30 oil. Synthetic oil has very good cold follow properties as well as offering excellent protection in extreme heat. So the SAE30 labeled oil that Royal Purple and Amsoil sell are actually mislabeled products. Meaning, for marketing purposes, they are sold as SAE30 weight oils, but if you sent them to a lab they would actually test as 5W30 or 10W30 synthetic oils. So in a round about way, they are almost identical to any other 5W30 or 10W30 synthetic oil sold by other manufacturers. It's just marketing, plain and simple.

Your typical 5W30 synthetic oil is actually a very robust product. For instance, on the Corvette, they found that the oil temperatures were very high when the car was ran on a track. The engineers advised that an oil cooler needed to be installed on the car. The penny pinchers got involved, and it was decided that instead of installing oil coolers on every Corvette sold, they would specify synthetic 5W30 Mobil 1 oil instead. And this "thin oil" performs pretty darn good at those extreme track temps, they have found.


Amsoil advertises there products SAE 30/10w30. I guess they do it that way to get around the mislabeling.

 

[bchannell]

I feel your pain. I'm obsessed with oil choices also. I'm trying to wean myself off all the hair splitting, and use some common sense, but hey, that's why we come here, we have lost our common sense.

The truth is, there may or may not be a "best" oil for any given application. It just may well be that there are several "bests" that will protect just fine, and you wouldn't ever tell the difference. If you take out all the anecdotal "it runs much better now with xyz oil in it" and my brother-in-law is an engineer for Trojan and he knows a thing or two about lubricants, then we're down to a lot of different oils work very well in small air cooled engines. I mean, just read the post, "post your latest small engine oil change" and you'll see that from 4 cycle weed eaters to 27hp garden tractors, people are using almost anything, and their equipment isn't blowing up.

I've come to the conclusion, after much putzing about oil, that 30wt, 15W40, and the like, make a lot of sense without going overboard and using a truly fantastic oil like Red Line. Does you mower really need Red Line? NO, it's been proven over and over, in sheer numbers alone. If you like spending a bundle on oil and it makes you feel good, there's nothing wrong with that, but you also can't prove it does any better than Rotella, VPB, or even plain jane Rural King 30wt, now can you? I try to use good protection without getting crazy. In my snow blower, I'll use a good 10W30 like Rotella T5. The only place I go syn is in my hydrostats, that don't get changed as often as engine oil, and have filters, to me that makes sense. But, in the end, you could go to Walmart, pick ST in the proper grade, and change it often, and never have a problem.