Would welcome opinions on oil treatments such as STP.

 

Never ever use STP. If you are going to add a modifier to your oil, I strongly recommend BG MOA. Those who are in the industry professionally, as well as Jaguar techs as well, will tell you the same.

 

Jag advises against any and all additives. That's good advice.

 

That's actually an inaccurate statement, for Jaguar now recommends oil fortified with liquid titanium additives, and is present in the additive package in Castrol Professional, and Castrol Edge, as well as Kendall GT-1. BG MOA is used by the dealer network.

 

And as always these new recommendations are not retroactive. BG stuff is not Jag recommended, it's a dealer upsell.

Big difference.

 

Nice try Mikey, but actually, it is. The liquid titanium additive is found to significantly reduce, and in some areas mitigate wear in areas like chains, cylinder bore, and especially the valve train. BG MOA is a proven performer that significantly reduces friction. You're welcome to stay in 1965 if you wish...

 

It's interesting... though the cars don't seem to suffer wear without it. (They fail due to a lot of other things, though.)

Fairly cheap to use in hope, I guess. You could buy more costly fuel, too. Oh, and oil. Don't forget nitrogen in the tyres.

 

.And that's the key point. What problem are we trying to fix here?.....

 

Please give info/basis as to why you are so strongly apposed to any oil additive in Jags. Specifically, 2005 XJ8L. Thanks

 

Years ago (30+ ish) Engines were no where near as tight on tolerances, and oils were lousy by today's standards. With the tighter tolerances, the need to have a lighter oil which moves through the engine quicker/more easily, is a lot more important. We had to use additives such as STP etc. due to the looser bearing clearances, and the excess wear older engines were prone to. Also there was a lot more oil contamination, as compared to modern engines, with the advent of much improved fuel injection. So with the High Quality Oils, and the High tech additives package already in them. Plus the tighter tolerances in todays engines. Additives are best left out of them.

JTS

 

Why do you feel the need to add something?

my advice applies to all engines, all cars.

Gasoline too.

 

Thanks Jacobra89, good info. I appreciate good reasoning and technical information vs just a warning to not do something.
My 2005 XJ8L now has elapsed about 135000 miles. It had about 114000 on it when I purchased it. Not sure of the prior upkeep although I've pampered it since ownership.I guess my reasoning on the STP is helping with wear since my Jag is getting on

 

If you wanted specific information from a technical perspective, that wasn't actually what you originally asked. Opinions can vary widely, and not everyone has enough technical training or background. STP is a conventional high-viscosity heavy paraffin based, long-chain mineral oil, with phenates. (calcium salt)

The reason we use lighter oils in today's vehicles, is multi-faceted. A 5W-30 will provide better scuff protection than a 10W-40. It flows faster under start conditions. (the greatest point of wear in any engine) You can use lighter oils to improve gas mileage, (much less energy is required for reciprocating mass to spin in a very light oil than it is in gear lube, and why many manual transmissions are now specified with ATF rather than heavy gear lube) cold start performance, and control for today's complex systems like VVT. You don't want to increase an oil viscosity, which is what STP does, as you can effect small orifice passages, which is a known issue with using heavy oils in VVT's where coking can occur. You then come to today's synthetics, which do have complex molecule construction where even using another weight of oil in the mix is not recommended do to the properties of viscosity improver additives in modern multi-weight oils. You don't combine a 0W-20 with a 5W-30. And you cannot create a 0W-anything without the use of synthetic stock, and no conventional oil can obtain that viscosity. The way in which the chemistry of the long-chain molecules can be affected. This is why you have to be selective in additives.

BG MOA, which I recommended, and many professionals in the industry know and use, including Jaguar dealers and techs, is a safe and very effective additive to greatly improve film strength, and it's high total base number increases the oils capacity to effectively neutralize acids produced by the combustion process. Once the TBN (total base number) is exhausted, then oil becomes corrosive. (the by-product of combustion is sulfuric acid) This is a primary consideration in oil change intervals where time plays a factor, not just mileage. A higher TBN equates to a higher safety margin for the time component.

All modern oils contain in some form and variety of content, additives, that's what makes it acceptable for use in modern engines. Knowing what to add and why, is not always understood by those who have little training or understanding in this complex issue, so "mileage may vary" widely by just anyone's "opinion."

 

This thread is humorous, just the other day people were making an oil additive recommendation in the below linked thread....

https://www.jaguarforums.com/forum/xj-xj6-xj8-xjr-x350-x358-28/help-me-identify-sound-196942/

 

Thanks. Very good "opinion", lol. Good education. Much appreciated.

 

Take any additive, I don't care which, take out all of the oil, and drop the pan and run it with 0 oil pressure, and compare it to the last video's performance. It's performance is self-evident, and why dealerships and techs who know, use it.

 

These engine are know to easily go 200-300k miles without significant wear or a notable failure rate. There is lttle justification for some '60s era snake oil.

The other thread involves an engine with a potential mechanical problem.

Apples and oranges.

 

Don't get me wrong Mikey, I appreciate your involvement in the forums as one who donates their time to the hobby, and you certainly have the right to your opinion, however, the industry as a whole, and countless service facilities, including the Jaguar dealer network, don't agree with your claim. If we are going to just be honest here, in prior threads, you have expressed you have no formal training, you're not certified by any credible automotive manufacturer, never been trained as a dealer network technician, have never worked in the automotive industry as a whole, so please don't be insulted when your assertions are taken with a grain of salt. If you have any technical or engineering credentials in the automotive or petroleum field, please correct me. Have a great day though...

 

I have never discussed my training or background beyond stating that it was 30+ years in aviation gas turbine engineering as this proves very little- anymore than you tooting your own horn.

Long on words, short on facts.

 

Mikey, there are very few in the arena of professional automotive service who doesn't know about BG products, it speaks for itself, and has for decades. You're simply repeating the same contention you did in the S-Type forum. If anyone is short on facts, you might want to look into the mirror. Have a great day.