Not every tune needs 99 RON.
This Renault Megane RS 250 was in with us for a custom dyno tune, with an intake and exhaust already fitted. The owner specifically asked for the car to be tuned on 95 RON, not something we'd recomend for best performance but we can certainly accomodate.
The starting point
The car rolled in at 260hp and 260ft-lb on the dyno, which is a touch above the factory claimed figures. That's fairly typical for these, they tend to come in slightly over the 250hp badge number with a couple mods fitted.
The results
After: 297hp / 330ft-lb
That's a gain of 37hp and 70ft-lb from a custom tune on 95 RON fuel. The torque gain is the standout here. 70ft-lb extra through the midrange makes a real difference to how the car pulls, and that's the bit you actually feel on the road.
Why tune on 95 RON?
This is a topic that comes up a lot. Most people assume you need to run 99 RON (super unleaded) to get a worthwhile result from a remap, and it's probably one of the most common questions we get asked.
The short answer is no, you don't.
Could this car have made more power on 99? Yes, absolutely. But the owner reasoning was simple and completely valid. They didn't want to have to think about where they fill up. 95 RON is available at every pump in the country. 99 isn't. If you're driving the car every day and filling up wherever is convenient, relying on 99 means you're either going out of your way to find it, or you're putting 95 in anyway and running a tune that wasn't calibrated for it.
A tune written specifically for 95 RON means the calibration is matched to the fuel the car is actually going to be running. No compromises, no "it'll probably be fine on 95", just a properly calibrated map for the fuel that's going in the tank.
It's a more practical approach, and the results still speak for themselves. 297hp and 330ft-lb on 95 RON from a Megane RS 250 with just an intake and exhaust is a strong result by anyone's measure.
Is 95 RON right for your car?
It depends on the car and what you want. We're happy to tune on either 95 or 99, and we'll always talk it through before we start so the tune matches how you actually use the car. There's no point building a map around a fuel you're not going to run consistently.
Thinking about getting your car tuned?
See what we can do for your car at www.WP-Tuning.co.uk
