How do you eco-drive a diesel ?

[blueflame]

I'm driving a Toyota Townace 2L diesel van a bit nowadays, and checked this thread for info...

I thought I'd try tuning the fuel pump screw, some intake/temp mods, and larger diameter tyres

But??? this thread has so much conflicting and high minded stuff here that I feel confused...

Getting around 7l/100km on a trip which aint bad for a smaller 1440kg van with high roof

Anyone for making a diesel economy sticky with relevant info?

[ecoxantia]

Not quite ready to write the definite guide, but I have been driving a diesel with a mpguino working (almost) properly. So far I can tell you:
-coasting is a good thing
-low revs are a good thing
-accelerate a bit harder than you might think would be best for "hypermiling"
-plan ahead! The less braking you can do, the better you're doing, I reckon.

See elsewhere for the usual tips- tyre pressure, aero mods etc!

Hope that helps

[blueflame]

So cold air intake is best for diesels? Even around 5-10 degrees C?

And less restrictive pod type air filters and free flow exhausts?

I may have interpreted incorrectly...

[ecoxantia]

I think its more about how you drive - the "nut behind the wheel" than any bolt-on mods like filters. In my experience it just ain't that easy to get these high economy figures I'm afraid! You need to change habits that are often deeply set.

In any case manufacturers are not in the habit of using restrictive parts...

But yes the colder the intake the better; you get more oxygen in the cylinder.

[tasdrouille]

Originally Posted by blueflame

So cold air intake is best for diesels? Even around 5-10 degrees C?

That debatable. Some say yes, I say only at high loads.

And less restrictive pod type air filters

NO! Keep your stock filter, unless you want your engine to ingest dirt. You will not gain mpg from a filter type change.

and free flow exhausts

Yup straight pipe from the cat converter (keep the stock cat).

[Vekke]

Have you ever tried push and glide in higher speeds 80 mph etc. I have and its frustrating because you have to shift very often and because the glide is so short. This leads to that it isnt fuel effiecient to do that in higher speeds... I think P&G is efficient below 55mph in my car at the moment.

Well today I was driving on the highway and tried different technique. First push on flat pedal on fifth gear. Then just release the gas pedal litlle bit so the speed starts to slow down circa 1mph per two seconds. Its guite tricky to get right pedal position, but I think I was able to get similar results that when driving 10-15 mph slower! My speed cycle was from 65-85 mph.

If you havent tried this kind of technigue please try it and tell me what you see . Any feedback is welcome.

[groar]

Originally Posted by Vekke

Have you ever tried push and glide in higher speeds 80 mph etc. I have and its frustrating because you have to shift very often and because the glide is so short. This leads to that it isnt fuel effiecient to do that in higher speeds... I think P&G is efficient below 55mph in my car at the moment.

I tried once with the scenic, but with the headwind I had the feeling to drive a wall so I DWL at 65-75 mph. Since then, my wife is the primary scenic driver and I drive megane on which I use P&G at mid speed with success : http://ecomodder.com/forum/showthrea...55-a-7097.html

If you havent tried this kind of technigue please try it and tell me what you see . Any feedback is welcome.

The tires pumped up to max sidewall and the rear wheel skirts are permitting to glide longer but the later are changing the feeling of the car so much that I'm now accelerating more and often over my max speed. In megane I don't have a real time FE display so only my butt-o-meter can tell me about my driving. If the coasting duration isn't longer than the pulse duration then I DWL (drive with load).

I'm in a 3 days week-end trip. My wife set a schedule forcing us to get the highway... Thanks to storms we changed the schedule and I avoided the highway

Denis.

[Piwoslaw]

Originally Posted by Vekke

Have you ever tried push and glide in higher speeds 80 mph etc. I have and its frustrating because you have to shift very often and because the glide is so short. This leads to that it isnt fuel effiecient to do that in higher speeds... I think P&G is efficient below 55mph in my car at the moment.

On a recent trip I had a 1.5km stretch of 130km/h road and I felt pressure from the other 3 people in the car to actually go there. With 4 people and heavy hiking packs it took a while to accelerate from 90 to 130, then I threw it into neutral and started to glide. By the time my speed dwindled down to 110 or 100, I could already see the 100km/h speed limit sign, so there wasn't reason to speed up again. I remarked to the Wife that on such a short stretch it's not worth speeding up to 130 km/h because it takes a lot of fuel and doesn't noticeably shorten our trip time. She mumbled something which might have been approval. But I feel that the next time we go that way, she'll say something like "Oh, here comes the 130km/h stretch!".

I'm hoping that, as in Groar's case, once my future aeromods are in place, P&G'ing at higher speeds will be more worthwhile.

--Adam

[Vekke]

Yes I don't either use P&G if the push is 7s and glide is around 10s. In this case I see the gain is so little I dont bother to stress my engine and gearbox...

But when I did the glide in higher speeds with little load the push is the same 7 seconds but the glide is around 16-25 seconds depending on the road conditions etc. This is also more relaxing to drive because you dont have to press clutch all the time.

I also think you need a turbo diesel to do this more efficiently?

This weekend I also cleaned up my intercooler which was pretty clogged. My IAT temperatures were rising in higher speeds so my max speed was 75mph. Now my IAT temperatures are 20 celsius lower than before and dont rise over 50 celsius. So you should clean your cooler now then to get the best gain of it .

[Piwoslaw]

Originally Posted by Vekke

I also think you need a turbo diesel to do this more efficiently?

In my diesel I start to feel the turbo in the 2100-2400 rpm range, but I hardly ever get into that range (never when ecodriving). I doubt whether the turbo helps in the 1400-1800 rpm range?

Originally Posted by Vekke

This weekend I also cleaned up my intercooler which was pretty clogged. My IAT temperatures were rising in higher speeds so my max speed was 75mph. Now my IAT temperatures are 20 celsius lower than before and dont rise over 50 celsius. So you should clean your cooler now then to get the best gain of it .

Hmm, maybe it's about time I unblocked it first? Then I'll see if it needs cleaning. If only I could find the time to make a temperature-controled grill block, then I wouldn't be worried about how much to (un)block depending on the weather.