VW T5 Multivan - Non-Intrusive Ecomodding
 

Hi there,

up to now, I lowered my L/100km by refining my driving techniques, that got me down to approx. 51 mpg or 4,6 L/100km on single trips. On tanks, I have seen no effects yet, but my first 'commute only' tank emptied with ScanGauge is due on monday (and looking good so far) so I hope to get good mileage.

Since I do not want to do EOC (diesel engine, still under warranty), the only thing lowering my consumption in the driving technique department is getting more routine, but I do not expect to see big improvements over the status quo.

Due to this, I have decided to do some non-intrusive ecomodding, which means all mods MUST be easily removable and leave no or only slight telltales of vehicle modification. The reason for this is a) the car is still under warranty and b) the german TUV is not really amused about non-certified vehicle modifications and c) the german police even less, so everything must be debatably harmless or invisibly installed, and for the 2-year checkup and for car maintenance all modifications must be removable without leaving telltale marks.

Agreed, this does not leave lots of improvements to do... first thing which came to mind is a cheapo grill block made of heating tube insulation which is simply cut to length and pressed into the horizontal inlet slits (pics will follow).

Did my first commute with this today. Conditions were OK, but not splendid; temperature at 4°C, no wind, some light fog. I did not use much drafting, only about 10% of the way. Best commute up to now was 51 mpg (4,6 L/100km), today I got 53,5 mpg (4,4 L/100m)! Surely, this is not an ABA test... the following days will show if this was a significant improvement.

Other things I am thinking about is an underbody pan, but two things speak against this... a) the front area is already rather tidied up by OEM and b) this would be a pain to remove and re-install after every check-up and maintenance.

We shall see.

so long,

tinduck

The promised photos:

http://img607.imageshack.us/img607/3747/grillblock1.jpg

http://img856.imageshack.us/img856/3606/grillblock2.jpg

Sorry for the poor quality, these were taken with my mobile phone in poor lighting...

As you can see, I used grey heating pipe insulation. Black would have been better, but I had these collecting dust in the basement, so I used them.

The black background in the VW logo is not solid but a honeycombed grill (you can see it in the second image if you look carefully) so the upper grill is not completely blocked which is a good thing for the intercooler and the AC radiator behind it.

For the lower grill I have to think up something else since the pipe insutlation does not fit.

BTW, this is my warm parking spot; you can see an air duct in the upper left corner of the first photo which emits air with 26°C. Outside temps are around 4°C at the moment, this should also help FE :-)

so long,

tinduck

Good going.

How about tire pressure? I would think changes there are quite stealthy, and rewarding in addition.

Tyre pressure is already at 55 PSI (max. rating 60 PSI) on my winter tyres, this should do nicely :-) I will not use the whole 60 PSI because of uneven tyre wear, I drive nowhere near max. weight usually.

In summer, I'll have to check how much my summer tyres sustain... up to now, I had them at appr. 45 PSI, I do not know right now how far I can go there.

so long,

tinduck

Nice and simple:) You cover the bottom grille either from the inside (good) or from the outside (better) with black or clear plastic). Once you stuff both grilles your engine temp should be 5-10°C higher, impoving its efficiency (hypermiling a modern turbodiesel usually doesn't allow it to reach optimal temperature).
Could you direct that warm air into the car and/or under the hood?;)

Oh, this is not really necessary since the car ist parked there for at least eight hours straight, so it is completely warm through and through... even at the low ambient temps at the moment, it is not advisable to wear too much cold-weather clothing when entering the car :-)

Concerning the lower grill block, I thought about clear or smoked plastic from the front with turnable hooks at the backside which will grip behing the grill bars. But I will have to find some plastic and edge-trim first...

so long,

tinduck

Wrap it with cling wrap

Hmmm... I doubt that the best wife of all will be d'accord with the optical impression of this method. Did I mention that the mods have to be wife-compatible?

I think I'll go for the smoked acryl / edge trim solution. But who has the time? :mad:

Concerning the upper grill block, I did some evaluations:

http://img195.imageshack.us/img195/6941/97799980.jpg

In numbers, on the commute to work, I get an additional 4,9 mpg; on the trip from work, it seems to yield 3,7 mpg (both compared all data before and after modification). It may even be a bit more since the weather has gotten colder which should normally hurt FE.

The last value would have been better, but the diesel particle filter (dpf) regeneration kicked in on the first 40 km of the trip which substracts a penalty from FE of about 5 mpg (0,5 L/100km). I would never have known without the SG :-)

so long,

tinduck