[Phil325i]

I don’t read a lot about this on the forum, but I have had an on-going, longstanding issue with slight (and it is only slight) ‘pinking’ (pre-ignition) in my direct injected N53 engine. I only notice it when driving with the window down and on one particular piece of road, namely on exiting a sharp, 90 degree slow-speed left hander which leads into an immediate incline. I’m in second gear and revs are low. The pinking passes quite quickly once revs rise.

I’ve done a lot of research but never managed to track down a reason. Until now. I’ve found a series of four videos by a US company called Driven Racing Oil. Here are the links:

Part 1

Part 2

Part 3

Part 4

In essence what the company found is that at low engine speeds, fuel and oil vapour in direct injection engines cannot sustain a clean, vapourised burn and this creates pre-ignition.

What particularly interested me is that they have created an oil specifically designed for direct injection engines and to minimise low speed pinking. I’ve not tried this yet, but intend to in the future. You don’t have to order from the US, as Driven Racing have a UK outlet, Anglo American Oil Company (aaoil.co.uk) who will ship on a next-day basis.

Here is the oil:

https://aaoil.co.uk/product/driven-d...lly-synthetic/

They produce three viscosities: 0W-40, 5W-30 and 15W-50.

I have no affiliation with either company but this is the first time I’ve found a meaningful explanation for this phenomenon and a possible solution. If you’ve also experienced this issue, I thought this might be of interest…

[Malteser_wfj]

It would be interesting to hear your findings after switching oils to see if your LSPI goes away using the Driven oil.

Are you going for the 0W-40 or the 5W-30?

[Phil325i]

Originally Posted by Malteser_wfj

It would be interesting to hear your findings after switching oils to see if your LSPI goes away using the Driven oil.

Are you going for the 0W-40 or the 5W-30?

I will continue to use 5W-30. I will let you know when I use the new oil. However...it seems the oil industry generally has woken up to the problem of LSPI (low speed pre-ignition) on DI petrol engines. There is a new spec (worth looking out for) called API SN Plus. Here's what's said about it:

API SN PLUS is the interim spec within the lubricants industry that supplements the API SN category for gasoline engine oil performance. It helps bridge the gap between current ILSAC GF-5 and future ILSAC GF-6 specifications. It was developed in response to auto manufacturers request to ensure gasoline direct engines have guaranteed protection against low speed pre-ignition (LSPI) events. LSPI is caused by high pressure build up in the cylinder of the engine which can damage your car’s engine.

I noticed the Mobil 1 I used at my last oil change was labelled API SN Plus compliant, and I'm deffo not hearing the pinking like I used to...