Really interested to hear what people who have owned an F-type for a couple years are doing with regard to oil changes. I am set in my ways and have typically never gone over 5K miles before an oil change but if I am being too **** I can try to stretch it. My prior Porsche service tech tried to argue that the engine "needed to keep the original oil for 10K" to set in properly, which I thought was crazy talk.
And with free included maintenance now, I assume Jag only pays for an annual change?

 

You will probably hear of a few different opinions as this has been discussed a few times.

Generally the impression i get is it is a good idea to change the oil early as you have been doing anyway as this is the oil with the highest amount of wear due to the newness of the engine. Makes sense really

But the counter arguments to this are some believe the orginal oil to be special running in oil and changing it to soon could actually be bad for engine wear.

Even with a modern engine i don't think you can go wrong doing it early but you will definitely have to pay for it as i wouldn't expect Jag to do it that soon.

Would be a lot more scientific to do a oil health check or something but there is no dipstick on our engines ha

 

During factory tour I asked production engineer if they use special break-in oil. I was told that they don't.

My car has now about 9,000km and I am on my third oil change.

 

Most likely no amount of hard proof will overcome this.

Jags have had 10K+ mile oil change intervals for at least 15 years. There's no evidence that this is in any way adventurous.

 

There is plenty evidence (e.g. premature chain failure issues, carbon build-up due to direct injection), you simply chose to ignore it. I can understand why - if I had S-type I'd probably run it until engine ceased. Why bother changing oil in it at all?

 

First, I'd agree the Porsche guy is nuts.

My version (am I'm sure there will be others)...

On a new car, I always do a first oil change on the early side - maybe towards the end of the break-in period. The idea is to flush away any metal particles that were polished off in the early run in period. This was particularly important in the old days when the manufacturing process wasn't as refined. I don't think (any?) brands officially call for this, but I still do it.

Past that, on a car with synthetic oil, such as the Jag's, I change the oil once a year as part of an annual inspection. I don't drive more than 10K/year, so it's well on the early side for mileage. Some would say to do it after a year, regardless of miles.

I once had a dealer try to convince me that even a synthetic oil should be changed every six months. I blew him off - equating it to Jiffy Lube wanting you back every 3-months/3,000 miles on regular oil. He readily conceded the point.

 

Dude..what?

 

Hypothetically, how might changing the oil earlier reduce carbon build up?

Also: in what way does direct injection promote carbon build up?

Could you explain the mechanism of this effect?

TIA

 

Irony. It happens at high latitudes.

A strong sense of same is what gets you out of bed on a winter's morning...

 

I have my Oil changed at the Dealer every six months because I live in SoCal, which is a giant parking lot, so I fall into the "severe conditions" category. I always chuckle to myself when I'm browsing Auto Trader when people say "100,000 miles, mostly freeway" which means their poor engine has been idling most of the time in hot weather.

Yes, engines are run at the Factory, but not run IN, they are tested for leaks, advertised HP but the test Cycle is very short. Too short to run it in.

It's all down to temperature, different parts have different expansion/contraction rates, heat results in expansion, which is why manufacturers recommend varying the Revs so the parts have a chance to get used to each other at varying temperatures.

In 2010 my Wife's Car suffered catastrophic engine failure at 20,000 miles, $18,000 worth of warranty work to replace the Engine. The Dealer had to call in a field rep to OK the work, they did two things, take an Oil sample and print out the service records which the Dealer had on their computer. There was no dispute and they gave the OK to install a new engine a few Days later.

There are a ton of Forum disputes about Oil change intervals and they almost always end with ".......peace of mind"

 

Based on the oil analysis that Blackstone has done on my oil, the oil in the car out of the factory is identical to the recommended replacement oil. Regarding first oil change, it makes most sense to me to change out the oil just after the recommended run-in period (3-5k miles). After that, it depends on the service the engine sees. 16k if it's easy highway miles (to keep the warranty), and much less than that for stop'n'go or high performance driving. I have the oil analyzed after each change to ensure that I'm not exceeding the safe life of the oil. First done at 3250, 2nd at 6750 (10k total), third will be done at 10k (20k total). I'll adjust future intervals based on service and oil analyses.

 

Empirically, we have seen DI engines from multiple manufacturers suffering extreme sludge problem at high oil change intervals. A number of them walked-back their intervals, notably BMW, but without compensating owners or extending warranty.

Now, if you want me to be more specific the problems that can be solved by more frequent oil changes are: restoring oil operational characteristics and removal of contaminants in the oil (notably - abrasive carbon nanoparticles). First leads to deposits, second leads to premature mechanical failure.

My understanding is that without DI both fuel and exhaust gasses come into contact with valves, but with DI only exhaust. Since fuel is strong solvent that washes out deposits, in DI engines this leaves intake valves and intake manifolds prone to buildups that are not present in traditional setup. Some of it is due to blow-by, as there is always some even if the engine doesn't burn noticeable amounts of oil. Now, the amount of blow-by is not linear - older the oil more of it you experience. As such, more frequent oil changes will exponentially reduce the magnitude of this problem.

If you are curious to read more on this:
http://www.sciencedirect.com/science...01679X15000432

 

In port fuel injection engines, the valves get washed with fuel, and if one uses a high quality (e.g. Top Tier) fuel w/ detergent additives, that "fuel washing" effectively prevents carbon build-up.

In a direct injection engine, the fuel is injected directly into the cylinder by-passing both intake and exhaust valves. That is believed to be the major cause of the carbon build-up in DI engines.

Oil has also been implicated by some, but the mechanism of it's contribution to the problem is far less clear.

 

So basically this is a problem with low-rent US fuels?

It seems surprising that this would be the case - particularly on a high end manufacturer. "The Black Sludge of Death" doesn't happen here, which is either something to do with the difference in climate (I live close to the area of the U.K. With the highest recorded temperature, but it's still 10C less than I've experienced in the US walking from the hotel to the rental car), or the fuel.

Minimum retail-able fuel here is 95RON. The formulation may differ to the equivalent in the US however.

 

Basically, this problem caused by prioritizing fleet fuel economy and emissions over reliability. The car design doesn't have safety margins for within-tolerance deviations in oil and fuel quality.

 

Precisely. It's pretty much theory and conjecture, far from being fact.

Octane rating has nothing to do with additive type or quantity.

The top tier marketing scheme is just that. They'd like for you to believe that non-top tier fuel is low rent garbage. A recent study by the American auto club (AAA) pretty much indicated that even the worst fuel (if you can find them) don't have much impact on performance or economy.

 

Uh, no it's not US fuel or ethanol-related, and our 93 is your 98 RON. As I tried to explain, it's related to the difference in the design. Port fuel injection cars had no carbon deposit issues running US fuels.

It's a worldwide problem, and all GDI cars, regardless of manufacturer, seem to be having the same issue. It's only now being noticed on a widespread basis because DI is becoming the norm on all engines.

 

No.

It is a problem with the way fuel is introduced into the combustion
chamber.

In DI it bypasses the intake valve completely and thus the intake
valve is never bathed in solvent. Just air.

As for a difference between continents, you may benefit from more
stringent oil specifications.

ACEA has a particular oil specification intended for DI spark engines.

 

LOL....Thanks for the grin today

 

Number 1. Maybe insulting a moderator is a bad idea?

Number 2. Both of your examples have absolutely nothing to do with oil change intervals.