I recently bought a Chrysler 300 with a 5.7-litre petrol V8, which the dealer recommended I use premium unleaded. The handbook states that 91 RON is acceptable, but 95 is preferred. A friend has been running his on 91 with no ill effects. What is correct?
You can run it on the cheaper 91-octane without any deleterious effects, but to get the best out of it you need to run it on the higher 95-octane premium as the dealer has recommended.