Marotta1;1577927 said:
So when did Mobil change their base stocks? I hadn't heard this was done. What are the better oils you're referring to besides German Castrol?
As for Mobil1, here's the answer they gave when
directly asked if they had switched from GRPIV to GRPIII:
Exxon/Mobil said:
As we're sure you can understand, ExxonMobil does not discuss formulations publicly,as this information is proprietary. We would rather focus on the advanced technology and proven performance that our engine oils and other products offer to our customers. Mobil 1 is the world’s leading synthetic motor oil and the one chosen by more original equipment manufacturers around the world as factory fill. We want those facts to speak for us so our customers feel confident they are getting a high quality, high performance product that provides ultimate protection to their vehicles.
If that's not "politician level" bullshit, I don't know what is... As mentioned, it doesn't mean Mobil1 is a bad oil. It's actually very good. There is just better available, why not use something better?
As for when, all of this happened years ago. It started right around the turn of the century when Castrol changed their Syntech product from GRPIV to GRPIII Hydro-cracked. Mobil took them to court and sued them on the basis they were falsely advertising a "dino oil" as a synthetic. Mobil lost the case because API didn't have a clear definition of what "synthetic" was. So Castrol's explanation that the oil "didn't resemble what came out of the ground anymore" allowed them to sell it as a synthetic. Just about all manufacturers of synthetics changed from GRPIV to GRPIII Hydro-cracked oil shortly thereafter, some of them very secretly or deceptively (see above) and some of them today still make some pretty questionable claims. For example; Take the name "Quaker State Full Synthetic Oil" - that's something you'd expect was a real GRPIV synthetic, right? Nope, it's a GRPIII. (I wouldn't run Quaker State in my lawnmower btw...)
Some of common the true synthetics on the market with my comments on each:
| Oil | Comment |
| German Castrol | Probably one of the best, cheap and sometimes hard to find. |
| Redline | Also top of the line, a little pricey, not too hard to find |
| Royal Purple | Very good, probably slightly behind Redline or GC but easily available, a little pricey |
| AMSOil | Great oil, but I don't like thier marketing, business model or prices |
Personally I run Royal Purple, which jdub refers to as a "boutique oil" -- meaning it's good, but he feels it's a little overpriced. I've had good results from it on my MKIV's and we used it exclusively at AAP/Supracentral with customer cars. This is not because I "feel" it's good. I run an oil analysis through Blackstone Labs on every change personally and I've run hundreds of customer cars through the same tests as well. It has shown very good results via testing for me.
I'm running an 8,000 mile change interval with a filter swap (Purolator Pure One) at 4,000. My oil analysis results and TBN tests prove this out to be perfect for
my car. I've got over 189,000 miles on my current 2JZ.
I'm convinced German Castrol is a slightly better oil, but availability is a challenge and my time is too valuable to me to go chasing around trying to find it. I've got 4 cases of RP in my garage at the moment and I can get it just about anywhere. If you find a good source, you can get it for around $6.50 - $7 a quart.
I also run RP 5w-30 in all of our cars, these include:
- 1995 MKIV Supra 189,000+ miles - Change interval 8,000 miles, Purolator Pure One Filter @ 4,000
- 1997 Ford Expedition 5.4 triton 260,000+ miles - Change interval 4,000 miles, Purolator Pure One Filter @ 4,000
- 2001 Toyota MR-S 80,000+ miles - Change interval 8,000 miles, Purolator Pure One Filter @ 4,000
- 1990 MKIII Supra 250,000+ miles - Change interval 4,000 miles, Purolator Pure One Filter @ 4,000
By the way, the Expedition looks like it's going to need a headgasket job soon. How do I know this? Not because of ANYTHING that you could detect from driving it or working on it:
You can learn what's going on in your motor
before it costs you money.
So run whatever you think will work, any of the oils mentioned above will do a good job, and have it tested. It makes a world of difference.
I'd suggest the following:
- Get some test kits
- Have a "Virgin Oil Analysis" done on whatever you intend to run so you have an idea on how far it will go.
- Test/change your oil the 1st time at 4,000 miles, heed the suggestions from Blackstone. They'll probably tell you your oil has X miles of life left in it and your next change should be at X number of miles. Try it. Send another sample in.
- Lather, rinse, repeat.
Get a test kit here:
http://www.blackstone-labs.com/
and never nocked at all for almost 10 days . Well the same day i did my oil change and my engine started nocking , they guy that i sold the supra to calls me. He said bad news the supra started to knock TOO. At this point im blaming it on the oil. Has anybody had some similar problems with MOBIL 1? Or changing your oil and engine starts nocking?
