DPFs, cars and buses...
Discussion
We have a diesel car with DPF. Until recently, I had no worries regarding the regen of this abomination as I used my daily commute Oxford-LHR to keep it nice and clear (ie, 75-90 mph both ways) Now, however, I have finally retired, the car only gets used for shortish trips with the exception of a fortnightly dash to & from Bovingdon via M40, M25 and a bit of A41. This hopefully will result in the DPF staying clear, though I do detect in between these runs from my mpg display that the system is giving the DPF its little necessary drinkypoos of derv to keep it in good order.
I have a couple of views/questions. First - our local buses proudly dispay on their ample rears the info that they are trapping particuates. So given that these bus journeys are relatively short, thus preventing them from a nice blast on a motorway at over 2000 rpm, how do their DPFs stay clear (assuming they are fitted with them)?
Second, we tow a caravan 3-4 times per year down to the coast for mini hols. I do know from my own experiences that the diesel makes a great tugger, which is why I spend a lot of time at the rear of queues rather than at the front, attracting frowns from my OH when she occasionally glances over at the speedometer. But - years ago when we towed with first a Renault 20TS, then later with a Cavalier SRI, both petrol, I do not recall bad MPG and they towed very well. This, together with the apparent good MPG figures from many of today's petrol cars, and even reasonable torque figures, leads me to think that for the few times we go away with the 'van we would be just as well replacing our current oil-burner with a nicely-specced petrol vehicle; also I have noticed that the petrol equivalents seem to be anything up to a couple of grand cheaper, and this is whatever make we are looking at.
Might now visit my couple of caravanning forums to see what they think for those like us who don't go away every weekend and not either for terrific mileages on those trips out.
Will also post this in the caravan section (mods - hope this is OK with you....)
Pete
I have a couple of views/questions. First - our local buses proudly dispay on their ample rears the info that they are trapping particuates. So given that these bus journeys are relatively short, thus preventing them from a nice blast on a motorway at over 2000 rpm, how do their DPFs stay clear (assuming they are fitted with them)?
Second, we tow a caravan 3-4 times per year down to the coast for mini hols. I do know from my own experiences that the diesel makes a great tugger, which is why I spend a lot of time at the rear of queues rather than at the front, attracting frowns from my OH when she occasionally glances over at the speedometer. But - years ago when we towed with first a Renault 20TS, then later with a Cavalier SRI, both petrol, I do not recall bad MPG and they towed very well. This, together with the apparent good MPG figures from many of today's petrol cars, and even reasonable torque figures, leads me to think that for the few times we go away with the 'van we would be just as well replacing our current oil-burner with a nicely-specced petrol vehicle; also I have noticed that the petrol equivalents seem to be anything up to a couple of grand cheaper, and this is whatever make we are looking at.
Might now visit my couple of caravanning forums to see what they think for those like us who don't go away every weekend and not either for terrific mileages on those trips out.
Will also post this in the caravan section (mods - hope this is OK with you....)
Pete
It's a bit of an ironic blow back...
Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
TheEnd said:
It's a bit of an ironic blow back...
Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
Thanks for that. It was just a mystery to me as the buses obviously spend most of their running slow & stop-start.Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
Also remember that a buses average road load is actually fairly high, even with the low overall average speed, mainly because well, it's a bus! (heavy, low geared and un-aerodynamic) Hence generally enough exhaust energy exists to carry out a regen light off without too much problem under most driving cycles, added to which generally a bus only does one cold start a day.
TheEnd said:
Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
Another possibility is that the engine does'nt have Adblue at all. A lot of buses and HGVs use EGR technology instead (hence no adblue).Mister3man said:
OP, what car do you have? Are they prone to DPF failure?
As long as you give it a good run every few weeks it'll be absolutely fine.
Saab 9-3 TiD 150. Never had any warning lights on regarding DPF but still considered the question of overall MPG which, since I stopped working, is a good bit lower and I feel this is due to it self-regenerating more often. My overall MPG between tank fills when I was commuting to LHR, obviously including our 40-50 miles of shorter runs on my four days off (work shifts were 4 on & 4 off), was 45-47 actual (51-ish on the display) and that included spirited commuting (51.7 miles in 45-47 mins when traffic light, 50-55 mins in some AM rush traffic!) Now it is overall 45-ish display actual 41-43 so I reckon several petrol cars would not be a lot worse even the 2.5 V6 ones. Now I am giving it a good blast frequently to avoid problems this seems to cancel out the otherwise good MPG. I would accept significantly lower MPG when towing, and of course this is only a few times per year. I admit that diesel torque is good but my Saab has, of course, a very narrow power band and for instance, the Mondy Tit X ones I have been looking at, much younger than my car, with quite a few more goodies, besides having those lovely xenons, has the same torque, ie 236 lbs/ft. As long as you give it a good run every few weeks it'll be absolutely fine.
TheEnd said:
It's a bit of an ironic blow back...
Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
Adblue has nothing to do with DPF's, it's to do with lowering Nitrous oxide emissions, essentially a by product of running too much EGR for emissions and creating a high combustion temperature, which makes NOx. Anyway, there's two possibilities with the DPFs, one is that they put in Adblue which lowers the temp of a DPF regen so they can carry them out easier, or another is the DPFs are removed and sent to a place that will burn them out and clean them.
These companies work for industrial applications, static engines, generators, etc where regen cycles can get a little awkward.
DPF's can run in a multitude of ways. Some will wait for the car to be sat at a certain rev range for a set time, others with inject a small amount of fuel after their main injection which heats up the exhaust gases to burn away the ash. PSA use a special fluid called Eyolys, which gets added automatically to the fuel everyime you fill up and helps clear the ash.
As for the buses, they will either do a forced regen on them from time to time, or they'll have another way. Depends who made the engine and emissions system.
PaulKemp said:
I think your fuel consumption is down simply to a different driving pattern now your retired and not doing long single commutes with few gear changes
Regarding my driving pattern - I enjoy the performance, and the pattern is pretty much the same but not as many long journeys!! Fair comment re gear changes. Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff