I have been using 5w/30 as the "preferred" weight in my 97 with 70K on the clock. Just being curious, I went to almost every oil company site I could think of with the recommended result for my specific car being 10w/40 year round here in the mid-Atlantic. One even recommended 15w/50 year round.

I realize 5w/30 is for the best for gas mileage but, with an aging car, I thought I would consider opting for the best engine protection in the upcoming hot weather and then change back to the 5w/30 in the Fall.

Do the oil companies (which all sell a 5w/30 oil) know best? I was thinking of the 0w/40, but that says European and seems to be more focused on the German VW/Audi/Porsche versus the English Ford/Jaguar. Also, I have a Nikasil engine and did not know if the Euro formula was good for a car like mine.

Of course, I may be answering my own question since the 5w/30 seems to have worked for almost 20 years. Even if I stay with the 5w/30, should I opt for the higher mileage oils when I reach 75K? My car does not leak a drop, but burns about 1 quart every 2500 to 3000 miles.

It's gloomy here today so that I thought another oil thread would brighten everyone's day.

 

There's no evidence of any problem with the recommended 5W30. The oil companies didn't design your engine, Jaguar did.

High mileage oils are only band-aids for engines that display signs of consumption, leaking, low oil pressure. They don't prevent or fix anything.

 

https://www.jaguarforums.com/forum/x...e+oil+guidance

75K is not high at all.

You might find that a 5W40 or 15W40 eliminates the need to
top up.

I have twice the mileage, and do not need to top up at all. I have
run 15W40, 5W40, 0W40 and 5W50. If I did not need the sub-zero
performance, I would be on 15W40 and be done with it. Richmond
would be qualifying territory unless you visit relatives in Wisconsin
or some such.

 

Oh Boy! Another oil discussion!

I have always used, on many cars over many years, something around what the manufacturer recommendation as far as weight, whatever brand I caught of sale and from where ever had the lowest price.

Never had an oil related problem.

My first cars' engines in the mid 20th century were done by 80k miles but the oils have gotten so much better as well as the engine tolerances that engines are expected to last at least 250k miles today.

My 4.6L, 330 HP Kia V8 goes 10,000 miles between cheap full synthetic changes down less than 0.25 quarts. Who could ask for more?

When the Jaguar was new (to me) the rage was oil testing. Companies that test oil for fleet vehicles rather than rely on mileage say that full synthetic oil only gets better at lubrication after 12k miles and before 18k miles.

Sure feel better now!

 

Ou/ Oil/ Oil. Preference. My car was produced in 1999. Many changes since then in oil quality. My owners guide states 10W- 40 oil for Mexico. My owners manual states 5w-30 as well as 10w- 30. other than Mexico. So, as my car is garaged all year, semi heated, above 35 degrees always, I use 10/40 in summer, 10/30 in winter, always Mobil 1 and been happy with results thus far. Factory is more worried about fuel EPA and Emission levels than they are of longevity of your Jag. I know its a tough decision, you decide. Hope this has been of some help.

 

I have been using 10w30 Mobil1 6,000mi between oil changes in both cars and I have no complaints.

Gus
www.jagrepair.com

 

The only real concern I would have using a heavier weight oil is tappet performance. As been mentioned EPA performance sometimes trumps longevity. I always use a synthetic because they tend to be more viscous before reaching temperature than a non synthetic....Good when its nice and cold out

 

Our engines don't have tappets.

 

Jaguar Workshop Manuals > S-Type (X200) V8-4.2L (2005) > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications

 

'Tappets' in this context is very different than in an OHV engine (cam/lifter/pushrod/rocker/valve stem) where the term more accurately applies.

Oil type and additives can have an adverse effect on OHV engines, not on OHC like ours.