This is an interesting topic. I too would think that better engine oil does not have the ESP formulation, but i'm no oil expert. I have read that some have run Rotella T Syn but suffered with oil consumption. Whats up with that? Rotella T Syn is also formulated for DPF equipped vehicles, but does not have the latest MB rating.
On the other hand I too have read that the EGR system also tends to get sooted up. I'm not sure if running other oil would increase the chances of EGR related problems.
What kind of mileage are you getting in your tuned sprinter?
Its not always that one oil won't pass a manufacturer's approved spec list.
Behind the scenes there can be a lot of politics and company policies at work
on both sides.
I can remember an "Incident" in the 1970's with BMW motorcycles and Duckhams Oils a UK independent blender.
They wouldn't supply BMW Motorcycles with their oil for approval simply because of the German oil filter BMW was installing on production for /5 & /6 models and as spare parts supplies was of poor quality. (flow issues)
They knew the filter was prone to collapse and had warned BMW about the issue which was ignored. "Surprise surprise" arrogant SOB"s!
Ultimately of course BMW concedes that they were wrong having had a spate of crank failures and an expensive worldwide campaign to rectify the issues for customers. British police forces were starting to buy volume fleets and it was causing technical sales concerns amongst other things
Equally the Chief Engineer at Leyland Trucks where I worked wouldn't approve another UK boutique blender due to recycling of old used oils in their blending activities; even though it met all API certification. Today of course we applaud this policy of recycling and Valvoline does this nowadays. Politics and often personal attitudes get in the way!
So its not all black and white behind the scenes.
Dennis
