Member Since: 24 Oct 2007
Location: Oireland
Posts: 4286
RAI - MPG LOSS
Evenin' all
Recently fitted an RAI to my motor and only when we had it on did we notice that Discowex's RAI had these slits cut in it - he bought it secondhand
Click image to enlarge
Thing is that I have noticed that my MPG is now down at 19.5 from mid 20's after fitting.....bit much I think.
Just wondering if the slits cut into the one above is a way of helping to keep the mpg up by letting more air in. Surely a LR part shouldn't cause that much of a drop Car serviced just before i fitted it so everything else okay I hope.
Any suggestions?A happy childhood ... is the worst possible preparation for life.
3rd Feb 2009 5:36 pm
ronp
Member Since: 29 Nov 2006
Location: North Yorkshire
Posts: 15245
I got slits in mine.
Thought that was the way they all came?...... always on the road less travelled 🚧
3rd Feb 2009 5:39 pm
Ken
Member Since: 20 Feb 2006
Location: Here
Posts: 10865
yep thats how they are
3rd Feb 2009 5:41 pm
tanters
Member Since: 24 Oct 2007
Location: Oireland
Posts: 4286
Thats what we thought but mine is blakety blank
The edges on the cuts on DW's looked rough so thought they were a mod of some sortA happy childhood ... is the worst possible preparation for life.
They all have those slits don't they? Mine has them, and I spent ages tidying them up as they were wonky like those in your pic.Previously:
2005 D3 2.7 TDV6 S
1984 90 2.25 Petrol CSW
1992 90 200TDi Hard Top
1995 Discovery ES 300TDi
2003 90 TD5 Truck Cab
3rd Feb 2009 5:42 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
Holes are extra
Seriously though , checked Marcons on Sunday and his is the same ..... slotted aswell.It looks like it was a DIY job though.
Last edited by Wex on 3rd Feb 2009 5:43 pm. Edited 1 time in total
3rd Feb 2009 5:42 pm
tanters
Member Since: 24 Oct 2007
Location: Oireland
Posts: 4286
same as in yours or mine A happy childhood ... is the worst possible preparation for life.
3rd Feb 2009 5:43 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
The slots are normal and so is the shonky work on them.
As for the loss in MPG... having a big lump of plastic stuck to the side of the D3 will of course reduce the airflow and thus MPG. I can still average 32 on a long run at normal road speeds if I want to. Sometime higher.
3rd Feb 2009 5:48 pm
tanters
Member Since: 24 Oct 2007
Location: Oireland
Posts: 4286
Here's mine
Click image to enlarge
Might be the case Simon, but I took my roof rack off the day I put on the RAI. The MPG should have recovered from that fact alone.
I is confused A happy childhood ... is the worst possible preparation for life.
3rd Feb 2009 5:54 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
mmm, thats not normal at all. Can you take it back or have them send you a new top section ?
I guess the holes would reduce drag, but also allow air into the engine as well
Do you have slots at the rear ??
Maybe they changed the design if its a new one ???
3rd Feb 2009 5:56 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
Elimination ..... cut slots and if improvement on current mpg then its your culprit.I'd expect some loss due to drag.
3rd Feb 2009 5:57 pm
tanters
Member Since: 24 Oct 2007
Location: Oireland
Posts: 4286
Its the normal grill at the back so no issue there.
Best thing to do is PM Nick....I'll be back A happy childhood ... is the worst possible preparation for life.
3rd Feb 2009 5:57 pm
Mossy
Member Since: 01 Jul 2005
Location: Hollyoaks, UK
Posts: 2683
So that's why my MPG is cr@p. D3 HSE V8...
3rd Feb 2009 6:06 pm
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
Talking of the RAI... where is the pre filter located ??
ISTR that there are only plastic bits and nothing that resembles a filter inside the unit.
Or does is just relate to the top slotted portion ?? All that would filter out would be trees and other large objects... anything smaller would fit through this.
3rd Feb 2009 6:07 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
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