Oil weights

[DJSHO91]

I've been using 10w30 in my 91' with no ill effects. I've driven in temps from the single digits/teens to above 100 and have had no starting problems or ticking noises. I have always found best results(not factoring in racing use) come from following the factory specifications.

 

[ViPER1313]

5w30 all year around, because that is what the motor calls for.

 

[jonheese]

Still be mindful of heat with either of dyno or synthetic.

I think you mean "dino" oil. Dyno oil is what happens when you throw a rod on the dyno.

lucas= snake oil

Won't someone please think of the snakes?!?!

 

[CademiaX]

If you are going to use M1, I'd again suggest 0W40 - no negatives compared to 10W40 and it gets to operating viscosity a little quicker because its not so thick when cold = being able to mash on it sooner! And its certainly got more Group IV in the package, so it should have longer usable life.

Good point(s)

2000 miles is all I give oil... just personal preference

I was also checking out Red Line Oil but that seems a bit excessive considering the price of it and the fact that I drive my car like an old grandma(most of the time )

 

[CademiaX]

Just found an interesting bit of info thanks to rubydist's comment that confused me

Group I is solvent extracted from crude oil. It's a mixed bag of hydrocarbons and in North America has fallen out of favor due to not being of very high quality compared to readily available base stocks that are improvements on it.

Group II is hydrocracked and dewaxed oil to produce more of the desired properties and it reduces unsaturated hydrocarbons, which reduces the tendency of the oil to oxidize and thicken out of grade. Most conventional oils in North America are made up of this.

Group II+ is an oil that would typically have very few unsaturated hydrocarbons and lower wax content. It may not be as fully processed as group III, but it is ahead of Group II for quality. Certain higher quality conventional oils use a higher proportion of this.

Group III is a heavily hydrocracked mineral oil. Most synthetic oils on the market are made up of this. The oil molecules are broken down through a variety of processes until they are much more like what has good lubricating properties, and removes or breaks down molecules with negative performance effects such as waxes. Pennzoil Platinum is the highest regarded group III oil on this site.

Group III+ is the extreme end of this, where the final product is basically nothing like any of the components that went into it, but it is still derived by heavily processing crude oil. An example of this would be Shell XHVI base oils. As well, oils are being developed on gas-to-liquids basestocks which would also produce extremely high quality group III bases, fundamentally synthesized but not falling into the definitions of group IV or V.

Group IV is PAO, which most consider along with group V to be a "true" synthetic. It is made up of base oils made from other hydrocarbons (often derived from natural gas) and is made specifically to be a lubricant, and does not have origin as crude oil. Mobil 1 and Amsoil are the best examples of these type of oils. They offer performance throughout extremes, resist oxidation, all kinds of fun stuff.

Group V is a blanket term for anything else, usually ester based oil. Red Line Oil is a common example of this.

 

[rubydist]

The data you referenced is "old" data, hence confusing.

Group III+ is the highly refined (hydrocracked) mineral oil. Performance of these basestocks rivals that of Group IV oils, but is not quite the same. Purists will say that "synthetic" oils have to be G4 or G5, but in practice G3 oils are considered synthetics.

One of the significant differences between G3 and G4 performance is that G3 oils need more viscosity enhancers to obtain wide viscosity spreads (10W40, 0W40, e.g.) The reason anyone cares about this is that viscosity enhancers have a shorter usable life than the basestock (they break down quicker in use) and this changes the viscosity of the oil.

In general, a 5W30 oil is made from a 5 weight oil that has viscosity enhancers added to keep the oil from thinning so much at operating temperature, hence keeping it as a 30 wt at temp. When the viscosity enhancers break down, the hot oil becomes thinner than the rating, which generally is not a good thing for the engine. When people talk about oil 'shearing' with use, this is conceptually what they are referring to.

Because of the significant viscosity enhancers required to make a 0W40 oil from G3 basestocks, and the likelihood that it will not stay a 0W40 oil over extended life, virtually all 0W40 oils are made from mostly G4 basestocks. A G4 basestock in the 0W40 weight requires relatively little viscosity enhancers, because of the native performance of the PAO. Thus, not only does a 0W40 oil have a more consistent viscosity over temperature than a 5W40, it is almost certainly more stable over time, such that extended drain intervals are perfectly safe and reasonable.

As a point of reference, I routinely run 10k miles oil change intervals with Mobil 1. I have done numerous used oil analysis, and have yet to have an example of M1 that has been "used up" at 10k miles. In a couple of cases at 12.5k the oil was at a point where it needed to be changed. So, running synthetic oil 2k or 3k miles between changes is literally pouring money down the drain (or into the used oil drum).

And, Mobil no longer uses G4 as the primary basestock for all of its Mobil 1 oils. Some of them have been tested by oil experts who report that they are mainly G3 basestocks. (Refer to bobistheoilguy.com for more data than you ever wanted to read on this topic....) However, it is a safe bet that any 0W40 is primarily G4 basestock due to the reasons I outlined above.

 

[_JR_]

I find the whole business of oil very confusing. The bobistheoilguy.com forum has enough information to keep me in my room for a few years learning about oil. I do find you get your branded consumers there (someone loyal to a certain brand) that clutters things up a bit.

I was trying to figure out what the best oil weight would be for use in the summer only. I store the SHO so i have a few less things to worry about. I could never get a solid answer on whats best for the summer, so i just stuck to factory recommendation of 5W-30. My 2007 malibu also takes 5W-30 so i just buy amsoil in bulk and get 2 birds with one stone.

What do you guys think would be the best oil for summer use (car would be driven aggressively and might see some track use now and then)?

Also why would you suggest that weight of oil for summer use?

 

[CademiaX]

Ok, well, I will just do some Red Line, I am lazy and make other people change my oil for $60, 5qts of 0w40 Red Line is $60... sounds good to me

 

[rubydist]

JR, a good 5W30 will be fine for year around in most climates, and a good synthetic 5W30 will be good for year around in any climate that you would want to drive your SHO.

imho, the xW40 discussion applies if you have an engine w/ lots of miles on the bearings, and you want to extend the bearing life - the 40wt oil will leak off the sides of the bearings more slowly than the 30wt, and therefore keep oil pressure and lubrication there longer.

 

[_JR_]

ooooh ok. That clears up this whole talk a little bit more. Well, a lot more lol. Thanks rubydist!

 

[CademiaX]

she is really liking the 0w40

--edit:

I just did my bearings about last fall...

She runs extremely smooooth with 0w40...

 

[YZF-Ford]

5W-40 Synthetic Rotella.