How big an effect do dirty intake valves in a DI engine have on fuel economy? Does anyone have any good sources that quantify the impact? I can only find general and vague information.
My 2018 WRX is rated 18/24, 21 combined, and has been seeing a steady decrease in fuel economy over the past 6-9 months, as shown in the charts below. I'm not sure what's going on to cause the decrease.
Granted, Q2 is a small sample size, but things have really been dropping since Q2-21. Q2-21 & Q3-21 are bit inflated due to more highway miles.
Whether or not you think it's DI deposit related, I'd love to hear your thoughts.
My 2018 WRX is rated 18/24, 21 combined, and has been seeing a steady decrease in fuel economy over the past 6-9 months, as shown in the charts below. I'm not sure what's going on to cause the decrease.
Granted, Q2 is a small sample size, but things have really been dropping since Q2-21. Q2-21 & Q3-21 are bit inflated due to more highway miles.
Whether or not you think it's DI deposit related, I'd love to hear your thoughts.