Originally Posted by Garc
I have a custom tune to run 91E0, which allows me to advance timing/spark(go-baby-go) with less opportunity for pre-ignition detonation due to less volatility in higher compression-ratio engines.
What does the truck manual say? I put in 87E10 for 2 years and my tuner still allows the ability to do so.
Why? It’s cheaper and I drive the vehicle every day. Ethanol(unleaded) can die off anytime soon, just an agricultural ploy.
1. Every vehicle can run any gas, regardless of octane or ethanol content- except specified by the manufacturer- means- if you vehicle is free to use E85 depends on manufacturer and the minimum of octane also is given by the manufacturer, where high compression ratio requires higher octane, which defines the self ignition point under pressure and heat.
Means: you have to use at least the minimum required octane, given by the manufacturer- but you can always go with higher octane- not that it gives you any advantage, but you can.
2. Every engine has a intelligent knock-management, including knock sensor, variable ignition point, variable valve train, etc. you don't need a tuner for this, except you change the engine significant- installing a turbo or compressor, for example. "enhancement" will not give you any advantages. The power is still made with more compression pressure- to get this, there is more needed than a tuner, a fake- CAI and some expensive exhaust parts. You might see a slight increase of response, but that's about it. Not worth the money, as the hemi is already a very good and responsive engine, even more combined with the ZF 8-Speed transmission. I doubt, it increases horsepower. Go to a tester and let them test the Torque and HP at your Truck. I hope you're not too disappointed after that. I tuned motorcycles for a long time- I know, what it's about.
3. The hemi engine is actually at the lower end of possible combustion pressure, which allows to install a compressor without any further engine modifications.
4. I don't know, where you get your values, but you seem to have a very "strange" understanding of technical facts or simply believe everything written on the package by ignoring the word "can".