View Full Version : How much will decat wreck your mpg ?
skitts
5th October 2011, 11:01
I have recently replaced my manifold, so now it's decatted. My fuel gauge is broken so i can't tell how much fuel i have :(.
How many miles should i be getting from £20 at about 132 a litre ?
Gandi699
5th October 2011, 11:12
Depends how you drive it
skitts
5th October 2011, 11:14
hardly ever goes over 3k tbh
Gandi699
5th October 2011, 11:32
I'd estimate 30-35mpg if its in good health, maybe a bit more
Proffitt
5th October 2011, 11:32
With a decat, it'll sound different (nice) and you'll drive so you can hear it.
So it will reduce your MPG.
No one can give you an exact figure.
skitts
5th October 2011, 11:35
Well i suppose so tbh it would be better if my fuel gauge worked :/ I will have to get it sorted then it should be fine!
rick_VTR
5th October 2011, 11:50
I fill up when the fuel warning light comes on.
I drive a 2002 VTR.
Approx £52.
The garage i use is 134.9 a litre.
Before decatting i was doing approx 350 - 450 to a full tank depending how i drove.
I decated the other week and filled her up when the light came on, next time the light come on i had done 375 miles, and i had obviously tested how much difference the decat had made so i thought it would have sapped the fuel but stayed roughly the same tbh.
So your answer is you wont notice much/if any of a difference from decatting :y:
devilsadvocate
5th October 2011, 11:55
Depends on your driving style
It wont make much difference in my opinion.
Maybe a few mpg less than you got before.
Liam_
5th October 2011, 12:32
You shouldn't notice any difference in MPG imo.
skitts
5th October 2011, 12:35
Ok well thanks for the help
saxova
5th October 2011, 12:36
Did you put the right lamba sensor in the manifold? and sleeved the other one to read clean air?
I didn't and it's defiantly overfueling, so loss in MPG.
Stuart85VTR
5th October 2011, 12:37
I had mine decatted for a while and didn't notice a difference on mpg so you should be good to go :)
Saxotim
5th October 2011, 13:09
my mpg improved with decat......
LSOfreak
5th October 2011, 17:07
my mpg didnt change noticabley with a decat
no one can tell you mate, becuase we dont know how you drive, if you do town driving, motorways, back roads??
skitts
5th October 2011, 17:12
Mostly town driving. I followed the guide on here for the manifold fitting. I have put one in the manifold but one is just sitting in my engine bay. I have not sleeved it yet.
LSOfreak
5th October 2011, 18:47
I fill up when the fuel warning light comes on.
I drive a 2002 VTR.
Approx £52.
The garage i use is 134.9 a litre.
Before decatting i was doing approx 350 - 450 to a full tank depending how i drove.
I decated the other week and filled her up when the light came on, next time the light come on i had done 375 miles, and i had obviously tested how much difference the decat had made so i thought it would have sapped the fuel but stayed roughly the same tbh.
So your answer is you wont notice much/if any of a difference from decatting :y:
thats really good mpg
i struggle to get 250 miles out of a tank with mine aroiund town :(
rick_VTR
5th October 2011, 18:52
thats really good mpg
i struggle to get 250 miles out of a tank with mine aroiund town :(
i dont really do much town driving tbh.
i travel approx 50 miles home on a friday night, bit of town driving maybe a trip off somewhere on the weekend with the mrs.
then drive 50 miles back to the barracks on a sunday.
the car doesnt move much in the week unless i go into town for a takeaway or pick up stuff for the sax in the evenings.
for an engine thats done 114k miles i think its doing bloody well haha.
but then i do look after it, service regular etc so.
Slugshead
5th October 2011, 19:57
No difference in MPG
saxova
6th October 2011, 09:12
Just got 90 mile's from 10 litres of fuel in my de-catted R.. Actually drove sensibly for a full 10 litres lol.
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