2-EHN Cetane improver

[rwb]

Is the 407 trip computer like the 406 where it would settle on the nearest MPG figure that was related to a *l/100km figure?

Always used to please me that my HDi90 used to do more MPGees than indicated. My Fords since haven't been so blessed.

It's exactly the same: two trips and instantaneous cycled on the right stalk button and rounded to the nearest l/100km. Also consistently under-reads but not by as much as my 406 did.

[rwb]

First tank had 25ml of 2-EHN in it. ...

Computer said 61.5mpg for the tank. MPG by brim-to-brim is 68.33

The last times the computer said 61.5 the brim-to-brim were: 68.9, 68.3, 68.9, 69, 67.6, 66.7, 67.9.

So on the first tank I think my verdict has to be: no difference.

Tank two. 75ml of 2-EHN.
Expecting a poor MPG again as a regen started in a queue on the M40, failed, and took what seemed like an eternity to finish.
Computer said 60.2mpg for the tank. MPG by brim-to-brim is 67.31

Last times the computer said 60.2 the brin-to-brim were: 66.55, 65.67, 66.24, 65.2, 67.67, 66.41.

Although it's up on what I was getting this time last year of 65.2 and 65.1.

So I think I'm sticking with no difference.

[rwb]

And another tank.

67.07mpg actual, 61.5 again on the computer.
Had some really bad traffic, a run out to Northampton, and a failed regen so that's better than I expected.

[rwb]

Computer 61.5 again. Actual 67.56.

[Welly]

You're getting 67MPG ?





Where do I sign?

[piglet]

Never got mine over 45. Now the boys got it it's 41

[PeterN]

My first one used to be up around 60 mpg most of the time but the two I have now although they will do 60+ on a long motorway run only seem to be doing about 45mpg around here, especially since the temperature dropped. Can't understand it.

Peter

[Doggy]

Mine does 50-ish in the summer and around 46 at the mo.
I think it's to do with excessive charge cooling in winter, but I'm too idle to stop the air getting to the intercooler to prove it.

[Welly]

My HDi also dropped by 5 mpg in the winter, I would blame the higher load on the electrics, over-cooling of the incoming air and traffic always seems worse in the winter so more start/stoppage.

I remember reading the ideal charge temperature for a diesel is 15 deg C, any lower and the flame front is 'quenched' leading to more demand for fuel.

Why is rwb's 2.2 twin-turbo so economical compared to the older single turbo? he's getting Hybrid-beating mpg's

rwb - would you like to do a month's swap with my Volvo for the sake of research? current average = 26mpg.

[PeterN]

I had a 2.2 C5, the old engine and the fuel consumption was dreadful, so much so that I changed it for a 2.0. which proved much better, and yet my son has a 2.2 coupe and the consumption is at least as good as mine and he drives much harder than I do.

I think at least part of the reason for increased fuel consumption in winter is the higher air density at low temperature causing greater wind resistance.

I can't see why both of mine should be so poor, they go OK and don't smoke, I keep meaning to try another set of injectors but haven't got round to it yet, I still have the original car that was so good on fuel so I suppose the best thing would be to fit the injectors from that.

Peter

[Doggy]

Why is rwb's 2.2 twin-turbo so economical compared to the older single turbo? he's getting Hybrid-beating mpg's

[rwb]

Indeed no welly, Welly.

[dirtydirtydiesel]

My first one used to be up around 60 mpg most of the time but the two I have now although they will do 60+ on a long motorway run only seem to be doing about 45mpg around here, especially since the temperature dropped. Can't understand it.

Peter

The main reason for the drop in economy is down to the different additives used in the colder month's
Due to diesel freezing

[PeterN]

Oh right, I didn't realise that the additives effected economy. Better than waxing though, I remember lorry drivers lighting fires under their engines in the '50's.

Peter

[rwb]

Tank 6. (Tank 5 at 75ml.)
Computer: 61.5 again
Actual: 70.1.

Here's a box plot of actual MPG (min, lower quartile, median, upper quartile, maximum) when the computer said 61.5.



So clearly this 70.1 is special.
I would have put it down to better driving conditions.

Previous with 2-EHN and 61.5 computer all above 67 and therefore in the upper quartile, so perhaps it is doing something?

Have put 150ml in the next tank.