So my question is... are people running 0w-30 or 5/10w-30 without any problems and is the engine responding better to the the more viscous oil at operating temp? Essentially 0w-20 and 0w-30 are same at cold?? and yet 30 weight is more viscous at normal operating temp. Wonder why then we all arent using 0w-30?

 

The cold viscosity choice’s primarily based on climate. A lot of wear occurs on cold start and the engine needs immediate oil flow. The 5 litre and newer variants have tighter tolerances and smaller passages which also needed lower viscosity BUT the primary reason for low viscosity was really for eco credits. As engines wear they need higher viscosity which the manufacturers or main dealers don’t really tell you.

 

Who all is running 0W-30 on your high mileage XKR and how has it responded? anyone done an oil analysis? Would be good to know!!

 

Interesting fact:
My LR2 with the turbo ecoboost 2.0l had 0W20 for the winter.
The one time I didn’t plug it in, its -37 (+ windchill) outside, and one start crank later, the top end and valves are toast. Crank is full of metal bits.
LR came to the table with a full engine and transmission and power transfer case replaced, at no charge.
Since then, nearing 0c, all vehicles block heaters (some inline ones) get plugged in, 1 hour before engine startup time. And I’m sticking with the 0W for startup.

 

As I mentioned in the post above, the cold viscosity matters based on climate. As for the operating viscosity, I’d base that on engine wear.

 

At -37C plus windchill, it is not a problem for the oil in general to start. An inline antifreeze does help a lot, but the cars really need an oil temperature gauge. They shouldn't roll until the needle gets into the green. Everyday we had to wait by the runway for 20 minutes until the oil temps got into the green, prior to takeoff. And the engines had dual sumps of oil, for that purpose.
At that temperature, operating a turbo can blow the heads very easily, just with a bit of wastegate lag. Then again we had manifold pressure gauges, to help prevent over boosting the engine.

 

Wind chill only affects items that create their own heat as the wind blows away the heat it produces.
Totally agree with everything else.

 

:-) Well aware of the effect of windchill on skin. Heat sink effect rates on metal do vary.
Merely sharing that I agree. Moving away from 0W is not in my books. The debate by many continues for the standard operating temperature weight.

 

Whatever viscosity you're using if it's a 5.0 make sure your oil meets the latest standards created for DI engines, they have additives specifically to encourage clumping of the soot (which is what wears timing chains and leads to what people call "stretch") and to prevent low speed pre ignition (LSPI). Putting in something you "swear by" instead of what has been specified and tested by the OE because your car has never exploded when using it seems like absolute hubris to me though.

There has been plenty of research and field experience on DI engines since these engines came to market, and significant improvements in the DI specific performance of additive packs.

I'd respectfully suggest that using STJLR.03.5006 oil, halving the Jaguar specified change intervals, and not mithering is the sensible option. Almost none of the wise man oil advice on the internet comes from someone with qualifications and/or real engineering experience in lubrication systems, powertrain design, or anything really. No, a mechanic who told you something in 1972 doesn't count

 

You are talking about ILSAC GF-6A.

 

Correct, or ACEA A7/B7 or API SP.

Whatever you want to do with viscosity you really shouldn't be using anything that doesn't meet these standards in a DI engine.

From memory API SP, ILSAC GF-6A and GF-6B all include test requirements for chain wear, which earlier standards did not have, and new standards for low viscosity cold start behaviour. API SP has stricter requirements around aftertreatment systems and emissions than GF6A.

OEM standards (such as STJLR.03.5006) often specify characteristics above and beyond these though, or prioritise certain additive behaviours over others.

 

DI seems to be so problematic by many car manufactures, that I would tend to avoid DI in favor of a good SC or turbo.
And chain wear in the past 4.2L engine, was poor design, not improper oil.
Statements have been made that using synthetic oil, doesn't allow any wear on the engines these days.

 

Well the problem with that is DI has so many advantages. This is my first DI engine but the increased power along with the increase in gas mileage was very noticeable. And if you ever plan to run Alcohol DI is tailor made for that fuel.

Think about it for a minute?? How can anything not wear? It has thousands of moving parts of course it wears.

I think your mistaking the 4.2L for the older 4.0L V-8 which had massive timing chain and tensioner problems. I had a 2005 STR with the SC 4.2L. Zero engine problems and I drove it past 130K miles. The 4.2L engine is possibly the best engine Jaguar ever made when you take into account the entire picture. Cost, durability, fuel mileage and power. It just flat worked.
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I still want to now who is running 0W-30 in their AJ133 engine and how is it doing on. Im at 140k and the damn things sounds like a Diesel. Getting ready to do timing chain, guides, tensioners, 100% refurbed Supercharge from Wraptor in UK...and I bought new High Pressure fuel Pumps and cam followers to replace as well in case this tick/knock blah blah blah sounds I coming from those bad boys. Would love to hear if the 0W-30 oil does well in our engines vs the 0W-20 if anyone is running it.

Loth