I haven’t eliminated the EV system….however, having driven C’s for better than 600,000 miles combined (three cars) I’ve not experienced an MPG loss like this - WELL OVER 10mpg loss happened pretty much overnight - but not last night - LOL I have eliminated brake drag and wheel bearing issues. The car has new spark plugs and air filter. There is a noice that sounds similar to ‘traction control/stability control’ activation coming from the passenger front only when the ice engine is activated. At least that is where I believe it’s coming from. Also, when watching the onboard “home” screen it seems to get extremely poor mileage - like 35ish mpg at 65mph (history says it should be getting closer to 50 than 40 at those speeds). ThanksMuch, and happy new year
The dash display, albeit skewed, is at least consistently skewed. Any new tires in the mix? Gas up somewhere other than the usual?
If your only hearing a noise when the engine is running; there's a high likelihood that's an engine noise your hearing. Traction/stability control, wheel spin issue, suspension issue; you should also hear the noise when the engine is OFF too, since the car is also moving. You'll need to put the car into maintenance mode to track down that noise. Could be something as simple as, something rubbing up against the harmonic balancer. Good Luck..
