Engine: D5: Removed my DPF

[Clan]

Originally Posted by Jim314

Correction of typo. Should be 5W-30.

Anybody know why Volvo would recommend 0W-40 for the 3.2L I6?

In the UK their recommendation is A5/B5 0w/30 for the 3.2. Your texas being on average a hotter climate could be the reason .

[michaelmckane]

Originally Posted by morsing

And another update - took the car out for its first DPF-less drive today and...

It doesn't work!

The potentiometer trick that is. Basically, the ECM looks at engine load and expected pressure differential over the DPF and it can't be fooled by a fixed resistance...

Everytime I started the car, I could do one acceleration, after that, the car would have virtually no power and the ECM would read out "DPF sensor pressure too low".

Too bad - I've now booked it in to have the ECM DPF code removed for a tiny fortune.

As to being DPF-less, it smokes A LOT when cold but is fine once warmed up. Smells a little when standing next to it idling as well.

morsing STOP car has no backpressure at manifold u need to put a plate with some holes drilled around 8-10mm at both ends of dpf ok you will still have engine management light on but car will accelerate and hold power uphill

[aslan]

Originally Posted by Jim314

The owner's manual of the XC90 3.2 gives a variety of choices depending on expected ambient temperature range, but gives 0W-40 as the overall best viscosity type. Mobil do sell a 0W-40 which they label something like European Car Formula, but 0W-40 doesn't come in an extended performance version.

Volvo's recommendation for a 40 as the upper number mistifies me.

Would your oil viscosity chart in your manual be the same as mine?

Oil viscosity.JPG

Like Clan said it is most likely due to your higher temperatures (which from google says can be higher than what he have here!) and not related to the engine. Mine is a 2.0T, a smaller engine but the manual still says XW40 is the most appropriate. I've been looking and I can't locate any 0W40 oil around here in any brand that meets the extended drain spec (ACEA A5). The local dealer here I believe use Castrol or Shell in the 40 weight which does not meet the ACEA A5 looking at their bottles.

Have you had any issue using 5W30 during your hot summer?

[Jim314]

The chart in the owner's manual of my 2004 V70 has only the top 3 bars--5W30, 5W40 and 10W30 with the exact same temp ranges, respectively, as in your chart.

I used to use Mobil1 EP/XP 10W30 because this corresponds to our temperature range in Dallas, but after thinking about the matter I changed to Mobil1 XP/EP 5W30. I decided the recommendations in the manual must have been arrived at to account for the limitations of standard oils, but didn't make sense for synthetic oils. It's my understanding that standard 'multi-viscosity' oils can lose viscosity near the end of service life and regress toward the lower number, but synthetic oils don't do this.

I don't push the engine in my car. If I were habitually driving at high power levels, then a -W40 oil might make sense because local hot spots in the engine might require a higher viscosity oil to keep an oil film. I think a -W30 whould give less internal resistance and so better fuel economy.

I have seen one analysis that states that the ambient temperature is irrelevant to the viscosity requirement at operating temperature because thermostat controlled liquid cooling keeps the engine internals at the same temperature regardless of the outside temperature. This would be the case unless the capacity of the cooling system would be exceeded, for example, by climbing lown grades at high power output.