95 RON and 99 RON fuel is something that is debated heavily in the tuning world. It’s not always clear if there is a huge difference between them, meaning you could be missing out on certain benefits.
In its most simplest terms, RON is the octane rating which serves as an indicator of fuel stability. It’s a measure of the fuel's ability to resist "knocking" or pre-ignition within the engine. Knocking happens when the air-fuel mixture in the engine ignites too early or unevenly. This can reduce efficiency and, over time, potentially damage the engine. With higher octane rating fuel, the fuel is more resistant to this unwanted combustion.
In the video below, we test the real-world performance difference between 95 RON and 99 RON fuel on two BMW G20 330e models. One is running 95 RON, and the other 99 RON. Both are tested at stock, and then again once we have installed our 3 channel chip tuning module.
Looking at the stock dyno graph below, we can see that the 330e running 95 RON produces just 280hp of peak power. This is 12hp less than BMW quote at 292hp. So we can already see the impact of running this lower octane, even before tuning. The other running 99 RON hits 303hp at peak, showing its running much more efficiently, producing 11hp more than what BMW quote.
With the module installed, we can see how things look on the tuned dyno graph below. The one running 95 RON is lifted to 371hp with 601Nm of peak torque, compared to the other running 99 RON which achieves 399hp with 617Nm of peak torque. This makes an overall difference of nearly 30hp and 16Nm of torque between the two, so a considerable difference to those peak figures.
If we take a look across the rev range, we’ll see how those increases are affected not just at peak performance, but how it’s being delivered throughout the revs. Looking at the individual graphs below, we can see examples of this.
2500rpm – 33hp gain vs 53hp gain
3500rpm – 38hp gain vs 81hp gain
4500rpm – 71hp gain vs 80hp gain
5500rpm – 92hp gain vs 116hp gain
This really does show the impact of choosing to run 99 RON, as we see a noticeable gain right across the entire rev range, which will make a huge difference when out on the road. Again, it’s proof that it not only makes the engine run more efficiently, but when it comes to tuning the engine, it make a huge difference to performance figures right throughout the revs, up to those peak figures.
Check out the full dyno test here:
For more information on tuning for your BMW, please visit: https://bluesparkautomotive.com/bmw-tuning
For more information on our rolling road dyno services, please visit: https://bluesparkautomotive.com/info-faq/rolling-road-dyno-tuning
Check out our recent blog post, where we cover the ins and outs of locked ECUs: https://bluesparkautomotive.com/blog/BMW-tuning-and-unlock-FEMTO
The chip tuning box featured in this blog can be found here:
