So my second post to the forums, go easy as I’m not a gear head as I am learning as I go and don’t have a grasp on the more complex lingo atm.

I have a stock 2015 evo mr- currently out of commission atm... but anyway, I use 93 octane, and even without driving it hard I will occasionally get the smell of fuel in the car on hot summer days. Gas cap is fine but I will replace it again after getting her back from the shop.

Injectors and fuel lines are also good and no issues. The car is completely fine in mornings and evenings and every other season, just not summer on a hot day.

I will add that I’m in Colorado at am driving it around at 7,000 to 9,500 above sea level and was wondering if this is affecting the air/fuel ratios (don’t have the tools or gauges yet to see poor or rich mixtures.)

wanted to see if I’m not the only one and get feedback. I read different things about avoiding ethanol mixtures and wanted to know more there because those comments were more on track use and evo’s beyond stock.

This is my daily driver but yes, I occasionally push it hard to enjoy driving my evo and feel a g or two, or show the other driving enthusiast on the road I’m having fun too. (Not street racing or breaking laws, to be clear for the sticky- I.e. just get to the road speed limit as fast as possible.)

 

If you aren't leaking fuel its likely going to be an issue with the evap system. That lines up with the time of the smell, hot days are going to cause more fuel to evaporate. I would expect that to set a check engine light though. Maybe the charcoal canister is leaking or something. You could have your mechanic inspect the evap system.