'Listening for ping' worked very well on old school cars that were not computer controlled. You'll NEVER (never say never) hear it on modern cars as the knock sensors will 'hear' it long before it becomes audible to humans and instantly correct it by retarding the timing. The retarded timing may become apparent as increased fuel consumption or lack of performance as you mentioned. One big benefit is not having to worry about engine damage as we did in the old days.

BTW- on the Costco subject- I do not claim to be an expert in the field. It happens that this is an old topic that I've seen beaten to death many times on other cars enthusiast boards I frequent. It always comes to the same conclusion however, no evidence to prove the case of 'bad gas' can ever be found and the retailer's efforts to dispel the widespread myth seem to backfire.

Oh well.

 

I have read a lot about using ONLY premium grades and gas in Jag;s. Well I recently purchased a 2000 XK8 and to my surprise the previous owner informed me he used regular grade gas.
So, the first tank I filled it with regular 87 octane and no problems. The second tank of gas was a 1700 mile drive back to Canada. No issues, lots of power and pep and the trip realizes 26.8 MPG. That is a US gallon as well. Pretty good speeds on the interstate as well, so not taking it easy and the average speed was showing at 67 MPH for the trip. Obviously, pretty much all interstate driving.

 

Your findings are no surprise at all, and thanks for chipping in!

 

Phew-what a debate

Going back to K&N air filters, my take on them is that any advertised increase in airflow compared to a NEW OEM air filter will only really become apparent at high engine rpm's & full thtottle-even then the differences are not likely to be that great & only amount to a few percent.

If you just drive normally then there's not really much to be gained, as the airflow through the filter in CFM's won't be high enough to take advantage of any advertised increases.

Of course, if you replace an old & dirty OEM filter with a new K&N filter, then you may well see an improvement in fuel economy-in the same way you would if you replaced a dirty OEM filter with a new OEM filter.

If there's one advantage to a K&N filter, it's that it can be cleaned at regular intervals & so will always be able to present the least restriction to airflow & won't clog up. Over time this may save a bit of money over buying new OEM air filters, but you're only talking about a few $ over many thousands of miles.

Unless you regularly drive around everywhere at full throttle at the redline with your engine tuned for more power, then there's not much to be gained from uprated air filters-the standard OEM item is fine for normal driving & will only become a problem if you don't change it at the service intervals & it becomes clogged up. In which case the problem is not the air filter, but a lack of proper vehicle maintenance

 

Yet another mpg / fuel / oil / type thread I see?

Fair enough, its a forum and car related obviously so open to discussion and debate.

The key words above are discussion & debate. We are all like minded people here to share views, knowledge and opinions
We DO NOT flame each other or name call, argue or fall out if member A differs from member B.....EVER!

The above will result in a moderator or myself getting involved, the thread being closed if necessary and or further action being taken, none of which we want. The essence is, please treat each other with respect at all times and have regard for someone else's point of view, even if it may differ from yours.


My take on it is as follows.....

I always ran my A6 on supermarket fuel, it was always cheaper and of course the points system they run offered "benefits"
At around 60k miles I switched from longlife servicing as I had changed driving style. Previously I covered long easy motorway miles and now do mostly stop / start small around town journeys.

The OEM recomends fuel filter changes at 40k and air filter also at around the same??

I started to change mine every year, no matter what.
Oil filter was again on longlife as was the oil, changed at around 20k miles......this too was changed to every year still using the longlife oil....In fact I also do a mid way point oil & filter change now as I sit at around 102k miles on the A6.

THE Air filter?
I've always used stock OEM and always been happy with no issues. As far as I can see, I've read many posts about K&N filters being over oiled and causing MAF problems, meaning a fairly expensive fix sometimes.
For the costs involved unless you're covering stellar mileage and running a fleet of vehicles I just can't see a huge saving. Just my point of view!

Re the fuel?
Having changed to using Shell V power diesel I have noticed a difference I can honestly say.
Using a combination of the onboard computer, the tank brimming method AND also using my fuelly account I notice my mpg has went up by around 2-3 mpg, the car seems to run smoother and is happier all round.
Yes it costs slightly more, but I'm happy to pay it and it works for me........some may dosagree and thats fine, thats their point of view and they're entitled to it.


Whatever your view, please interact with each other with care & respect at all times.

Thanks