Mobil 1 20,000 mile oil change.

[RalphVa]

Did 10k oil changes on our VW TDI. That's what they recommend. Used Castrol 5w30 from the dealer for it because could not get M1 ESP 5w30 locally. Online was A LOT more expensive.

Did first 10k change to M1 0w20 on the Mazda3, as recommended. Changed to M1 0w20 on the MX-5 and plan to go at least 8k or 1 year on it vs. 7.5k and 6 months they recommend.

If I drove enough to put 20k in 1 year with M1, I'd do it. Think this is what is recommended by Benz.

Oil has improved by leaps and bounds since the old days of 1k and then 3k changes. I gradually went up to 5k changes on the 1983 240D we had for 25 years.

On the Mazdas, their PCV systems purge the acidic blowby gases (CO2 plus H2O, which would make carbonic acid) vis a line after the air cleaner to the valve cover. The PCV valve takes right off the crankcase to the intake manifold. This is another way engine makers are creating longer oil drain intervals. Most cars (our 2.7 L Tacoma, for instance) just have a line from the valve cover to the air line just before or just after the air cleaner. This doesn't provide really any sweeping air purge of the acidic gas.

Ralph

 

[2ndhalf]

Meijer's has been running a special on their M1 Extened Performance (good for 15k) for $35ish and a free extended life M1 filter.

I have been doing this lately and changing it before 8k just because that is what I feel comfortable with. It is a very good deal for a very high quality oil and filter combo. My car now has over 106k and did not use any noticeable amount the last time I changed it; I run the little 2.4L hard too.

Mobil 1 Extended Performance Oil | Mobil Motor Oils

 

[trooper632]

I go 20,000 between oil changes, but do a oil filter change at 10,000. Run Amsoil 15w40 and have been doing this for the last 12 years on every truck we have owned, Chevy, Ford and now Dodges, all diesels. Run between 300,000 and 500,000 miles on every engine before we trade out vehicles. Never had an engine problem due to oil.

Maybe so but i figure a 10 dollar oil filter wont break me

 

[kenmac]

A TBN of 3-4 at 10K miles means you have more life left in the oil.

very little life

 

[Robin Veerman]

A TBN of 3-4 at 10K miles means you have more life left in the oil.

Standard UOA is that an oil change is advised when the TBN as at half or less of original value, among other issues of course.
Dutchy