It seems understood that OEMs program their DI/TGDI engines to richen the fuel/air mixture in conditions where LSPI could occur. This question isn't about that.
All modern engines have knock sensors that detect "pinging" or spark knock other than LSPI. In the pre-DI/TGDI days, the response to detected pinging was to retard engine timing. Is this still true with DI/TGDI engines or are they programmed to enrich the fuel/air mixture instead?
In my DI Honda using the specified 87 octane fuel and driving long distances into a stiff headwind at Interstate speeds (think westbound I80 across Nebraska ) will result in a noticeable increase in oil level, presumably from fuel dilution. After considerable experimentation I've found that 91/93 octane fuel seems to prevent this. This leads me to believe that low revs/high load under these conditions does induce some pinging with 87 octane, the mixture is richened in response and fuel dilution results.
I know we can't look into PCM programming, but does this make sense?
Thanks!
All modern engines have knock sensors that detect "pinging" or spark knock other than LSPI. In the pre-DI/TGDI days, the response to detected pinging was to retard engine timing. Is this still true with DI/TGDI engines or are they programmed to enrich the fuel/air mixture instead?
In my DI Honda using the specified 87 octane fuel and driving long distances into a stiff headwind at Interstate speeds (think westbound I80 across Nebraska ) will result in a noticeable increase in oil level, presumably from fuel dilution. After considerable experimentation I've found that 91/93 octane fuel seems to prevent this. This leads me to believe that low revs/high load under these conditions does induce some pinging with 87 octane, the mixture is richened in response and fuel dilution results.
I know we can't look into PCM programming, but does this make sense?
Thanks!
