N62 engine software. but yes, I guess I get your point.

It's not counterfeit.The new management allows self installed Dinan products. There is no way of knowing if the Dinan tune is the same as before or not. IMO it is a different tune as all Dinan tunes went with other Dinan products to get the gains. There was no tune back then that there was only a 6HP and 6TQ. All tunes increased performance more.

Since air fuel mix, even with a tune, is still managed by the BMW components I suspect the tune has nothing to do with your problem. I wouldn't buy any parts until you verify the core problem via troubleshooting. I would monitor air/fuel mixture. You could also do some Dyno runs that should find the cause.

I've tried multiple troubleshooting methods sadly, as have my mechanics.
a Dyno around here costs hundreds and therefore it would be cheaper just to see if the Dinan software could make a difference. I was thinking a different fuel map may be what is needed... hence why I'm debating flashing the ECU/DME back to stock first...

good call,
I have an Autel device I can raed and record AFR values on. I'm not sure how to do it with INPA.

Since we want maximum horsepower and don't want to burn a valve, you bet we do.

As I mentioned, both my M54 engines have been running strictly regular fuel for 13 years now. My guess is if a valve would burn because of my choice of fuel, it would have burnt by now. About 150,000 miles on the X5 and 175,000 miles on the E46 running regular fuel.

Not going to say it is the best fuel to run, but paranoia about burnt valves running regular unleaded has been debunked to say the least.

I'm glad it hasn't bit you. Others have not been so lucky.

Not sure I have any luck. 2 separate vehicles, 2 separate engines, closing in on 200,000 miles each running regular fuel, no issues.

Regular fuel in a high combustion engine can lead to detonation but knock sensors on the BMW will signal the DME to compensate the timing map to eliminate any detonation.

Keep in mind I do not do any real spirited driving, point A to point B is all my street cars do. But again, I have never heard any pinging or detonation since moving to regular.

Dinan D900-45X kit (Engine software)
 

Running regular fuel is definitely not going to burn valves. The E53 is capable of running 87-93 octane fuel. Higher octane fuel will reduce knock, period. If Boost is simply cruising his E53, regular fuel is actually a better choice. It has less carbon, things will be cleaner, and it’s the most efficient fuel grade.

This is an important point. He is not at redline every stoplight. Pinging on an advanced vehicle like an E53, is an obsolete thought. The engine management system is in full control of all environments on a stock X5, provided the OBD system is NOT riddled with faults. If there is an extreme, unfavorable environment, in conjunction with poor fuel, then maybe issues could arise.

Now use my E53 as an example. Regular fuel will knock if used, however the DME will still pull timing. So, the issue now becomes heat. The blower is hot, the engine is hot, and the regular fuel is burning hot. Heat is the real issue, it creates pressure. This is what can cause catastrophic damage. When running E85 105 octane, again the DME adjusts timing, because the fuel burns considerably cooler than regular. So instead of retarding the timing, like in Boost’s case, it is advancing it in my case. The reason is, the higher octane fuel creates a colder environment. However, this fuel type is inefficient.

If you have a stock setup, any fuel grade will work. Turbos, and superchargers require a cooler burning fuel. Also, pay close attention to your compression ratio. That will also dictate whether you’ll need to use a higher octane fuel as well.

M vehicles should always use premium. Generally because they have higher compression ratios, or they are forced induction.

JMHO

Edit: :beerchug:

I would usually run Shell mid-grade in the E53 unless I was towing or making an extended highway trip. Then I wanted to maximize timing advance for best mileage and avoid detonation with the higher engine loads. But always Shell to keep injectors and intake valves clean.


My F15 and the CEO's F32 only getting premium though with those turbos.