hal9000 Report post Posted November 12, 2022 When I was doing the once over for the 14 ffh SE that I just bought, one of the things I noticed was that there is a lot of exhaust soot deposited on the underside of the muffler, apparently from the weep holes, and a lot of soot deposited on the underbody near the rear bumper cover. It's a former fleet vehicle so maybe it spent a lot of time idling, but not sure. It did have an O2 sensor warning showing on a code reader before I test drove it, but that cleared out after ai drove the car a couple miles. ... I figured that worst case it might need an 02 sensor, but then I googled an there seemed to be a lot of people asking about exhaust soot on these cars. Is this a normal thing or an indication of something amiss? Also, if anyone has an estimate of what a "typical" number or ratio of operation hours/vehicle miles is, that might give me a ballpark for how much idle time the car had... Thanks all! Quote Share this post Link to post Share on other sites
mwr Report post Posted November 12, 2022 7 minutes ago, hal9000 said: Also, if anyone has an estimate of what a "typical" number or ratio of operation hours/vehicle miles is, that might give me a ballpark for how much idle time the car had... What would "operation hours" be and how would you determine that? Quote Share this post Link to post Share on other sites
hal9000 Report post Posted November 12, 2022 1 minute ago, mwr said: What would "operation hours" be and how would you determine that? On most newer vehicles you can find an hour counter somewhere in the settings. I think I scrolled past it on this car already, but don't remember where I saw it in the menu. It's not hard to find though.... It's essentially either a "key-on hours" or "engine on hours" counter in most cases. Higher than average hours of use/mile would indicate a lot of idle time or very low speed driving. Lower than average would indicate a lot of highway use. Quote Share this post Link to post Share on other sites
billford Report post Posted November 13, 2022 22 hours ago, hal9000 said: Also, if anyone has an estimate of what a "typical" number or ratio of operation hours/vehicle miles is, that might give me a ballpark for how much idle time the car had... Thanks all! According to Ford and others, 1 hour of idle time = 25 miles of driving This mainly applies to stationary engines or vehicles that idle for long periods, such as utility trucks. Quote Share this post Link to post Share on other sites
hal9000 Report post Posted November 13, 2022 In terms of wear I can believe that, but it's not quite the question I was asking. I'm not sure what the lifetime average speed of most cars is (obviously it's going to vary to some extent), but that's another way of thinking about it. For example, if you ONLY drove on US highways at 75mph, then at 75k miles the hour count on the car would be 1000 hours. If you only drive in neighborhoods at 25 mph, then you'd see 3000 hours at the same mileage. If the car idles for 6 hours a day and then drives at 35 mph the rest of the time, your hour meter is going to have at least 10000 hours for the same mileage.... It can be a vague but informative tool, especially if you know what to call "typical". Quote Share this post Link to post Share on other sites
hal9000 Report post Posted November 19, 2022 Outside of the hours/idling question, can anyone shed any light on the sooty exhaust in general? Is it typical on these cars or related to a known problem? The seller had another identical fusion (higher mileage, worse cosmetic shape) that didn't have the soot build up, but that's just one data point.... Quote Share this post Link to post Share on other sites
MeeLee Report post Posted December 30, 2022 The average car speed is 40mph, or half your max speed. If you do highway only, your average speed obviously will be very close to the top speed. If you drive in the city only with 30mph speed limits, your average speed will be closer to 15mph. Most people will range between 20 and 40mph average speed. Soothy exhaust is because if your engine never gets hot enough, it'll need to inject more fuel. This is done during cold starting, (extreme) cold weather, or when you drive mostly electric, thus long phases of electric driving, and short phases of gasoline (especially true for the energi phev). Short and slow trips can also be the blame, where the engine never gets taxed. Once you do more highway trips, sooth should lessen Quote Share this post Link to post Share on other sites
