How do you eco-drive a diesel ?

[mcbota]

Many thanks to All of you, for precious advices. Most of the roads in the city are flat, and we have a lot of stop lights( I assume we can be in Guiness Book for the city with the most numerous stop lights/ citizen))), so you anticipated my question: worthy to coast in neutral from stop light to stop light, or in gear ( in gear is harder, the distance between stop lights being around 250-500 m)? I am not sure how is the thing with ”load and low rpm” and how can I realize this without being too low in rpm! I stilll learn and I thank you for being good teachers!

[oldtamiyaphile]

Originally Posted by mcbota

worthy to coast in neutral from stop light to stop light, or in gear ( in gear is harder, the distance between stop lights being around 250-500 m)? I am not sure how is the thing with ”load and low rpm” and how can I realize this without being too low in rpm! I stilll learn and I thank you for being good teachers!

Keep it in gear if you need to stop. My T5 uses less fuel gliding in gear than coasting in neutral even factoring in the engine braking (I would have never thought this was possible previously - but it's heavy ~1900kg with a full tank & driver, fairly aerodynamic [0.33cd] and of course being a diesel there's little engine braking to speak of, esp in sixth gear at 1000rpm - it will coast a really long way). Keeping it in gear also means I can do micro pulse and glide, only droping speed by 5km/h, this method is working better for me than engine on Neutral coast, and it can be done even in heavy traffic.

If I'm driving in 4th or 5th and want to glide, I'll upshift to sixth to minimise engine braking while staying in DFCO. If I'm turning or see slow moving traffic ahead and know I'll need 3rd gear, I down shift ASAP so the gear is ready when I need it, the modest increase in engine brake saves the friction brakes, and the higher RPM means I stay in DFCO longer.

For load, low RPM= high load (generally), my T5 cruising on level ground at 60km/h & 1100RPM is already at 80% load. At 1300 RPM (5th gear) load drops to 65. If I didn't have a Scanguage I'd suggest keeping the revs at 1200-1300.

[cRiPpLe_rOoStEr]

Originally Posted by oldtamiyaphile

I know some diesels now have Stop-Start, but I wonder about how the DPF will handle that kind of mistreatment. I realise that idling isn't really helping keep DPF temps in the butter zone. I'm still tracking my DPF regen frequency, once I get some data, I'll try a bit of engine off and see if I get more frequent DPF burns.

DPF really sucks. Anyway, those newer ceramic glowplugs and exhaust variable valve timing (emulating a non-cooled EGR) are also useful since they provide quicker warm-ups, and newer standards for Diesel fuel with higher cetane ratings also generate a lesser amount of heavy particulates to clog the DPF. What bothers me is how the automakers compromise the efficiency and adaptability to alternative fuels to go cheap on those emissions aftertreatment setups which are a plague even when running on regular Diesel fuel.