U can use Ron 95.
When our trek's ECU detects any detonation, it will retard the ignition timing, and resume normal timing once it everything is ok. U can easily feel this happening when U're under boost or load. Example: going up a long slope along Karak highway, suddenly the car just feels under-power no matter how much gas U step on it, boost just wouldn't climb. On the other hand, if U're a easy driver, spend most time cruising, only accelerate the car occasionally, and doesn't drive the trek like a nut, Ron 95 is sufficient.
BUT....if U're the type that drives the trek under boost constantly, then better stick with Ron97.
I've been using Ron95 since day 1. Here are few things U can do to further prevent detonation.
- Keep your stock air box, replace with a drop-in filter if U want better airflow. Dun recommend open pod air filters, they suck in hot air inside engine compartment.
- Upgrade to a FMIC, the top mount intercooler is a junk, it hardly cools down the intake air. It's exposed to heat soaked under the hood, working more like a heater to me.
- Look for a larger & more efficient turbo. Boosting beyond 0.8bar out of the tiny TD04 is "overworking" it, the tiny snail will only spit out even hotter air. HOT INTAKE AIR TEMP promotes detonation!! Each turbo has its sweet spot, meaning most efficient pressure range. Increasing boost will only get U more HP up to a certain level only.
- Replace the thermostat with a low temp thermostat unit. It will help U "remove engine heat" earlier, keeping the engine operating temp lower. This really works & shows on the coolant temp gauge!!
- Replacing the radiator with a better unit will help too. I'm still using stock ones though, find them sufficient for my needs.
- Thermal coat intake manifold, so that it doesn't conduct engine compartment heat to the air going into the combustion chamber.