decat mpg vs cat mpg

[Scunny_182]

before any1 says ive search and couldnt find owt.

only the fact that some people say it doesnt make a difference and others say its does well....

resently got a clio with a ktec exhaust and decat, was too loud so i got a sports 200cell cat fitted at exhaust uk.
heres what my calcations work out at and trip is a little out but only by about .2/3.

DECAT MPG - 28.8 with a full tank and getting 280 miles before petrol light comes on, going to manchester and back from scunny and town driving.

CUSTOM SPORTS CAT MPG - 33.9 with a full tank and getting 299 with a reading of 8.8 before petrol light comes on. motorway and town driving.

in my option, having a decat decreases ur MPG and have a cat increases it.

 

[Lewin]

Not in my case. With or without a decat I get around 34mpg. If it does decrease, it's not by much.

 

[Topgeartom]

On my daily commute of 7 miles at an average speed of around 25mph i get a consistent indicated 32mpg with or without decat - fitting it made no difference.

 

[laz5758]

On my daily commute of 7 miles at an average speed of around 25mph i get a consistent indicated 32mpg with or without decat - fitting it made no difference.

Apart from that it's loud as FOOK!

 

[Topgeartom]

It is admittedly silly loud when the right-hand pedal is applied.

 

[Aluco]

Which with Tom being Tom is every time he sees a female pedestrian

"LOOK AT ME GOOOOO !"



ps. Thanks for the wiper blades gawjus.

 

[Riley!]

only lossed 2-3 mpg with de-cat. Went form 36-37 down to 33-34

 

[Scunny_182]

guess its different with every1 still...

 

[ianeire]

Made no discernible difference to mine when fitted.

 

[Andyman]

OP:

Manchester to Scunthorpe, guessing you went M62 motorway? To get 28.8 on a long motorway run sounds more like a fuelling / lambda issue. Was the car mapped? were one of the lambda's unplugged? was the decat blowing slightly?

You should have been getting easy mid 30 @ 70 / 80mph to high 30's on a long motorway run regardless of cat situation.

 

[st3ve]

You can't really test this kind of thing fairly, it's mostly a matter of opinion, it all depends what sort of journeys you do and how much you press the loud pedal which tbh is different from one person to the next.

Decat all the way for me though, I don't care about a couple of mpg as I love the extra noise but I don't do silly mileage in it so I can live with it.

 

[Gaz85]

With my decat I have not noticed any differences, but hard to tell as I dont drive the car the same all the time. No major differences anyways.

 

[laz5758]

My car is random, driving at 65-70 with cruise control on, I get around 38mpg! But last week when I was coming back from the parentals, going at a fair pace (I was the filling of an RS4 and Focus RS sandwich) I was getting 34. Is my car broken?!!

 

[Jonny1*2]

motorway miles you should be hitting the 40mpg figure really. 70 all the way, easy on the right foot. Easy. Decat should make no difference what so ever.

 

[Scunny_182]

OP:

Manchester to Sc**thorpe, guessing you went M62 motorway? To get 28.8 on a long motorway run sounds more like a fuelling / lambda issue. Was the car mapped? were one of the lambda's unplugged? was the decat blowing slightly?

You should have been getting easy mid 30 @ 70 / 80mph to high 30's on a long motorway run regardless of cat situation.

Cars not mapped n I think the sensors are ok. Yes it was m62. The second mpg with the cat I did rotherham n back twice over the weekend to play hockey. That's a 80 mile round trip so 160 miles of that tank was motorway. Trip was saying 37/38mpg.

What fo the lambda actually do?

 

[barker22]

u want to drive the same stretch of road twice, preferably with the same outside temperature and little/no traffic. one time with the cat on and one with de-cat. stick the cruise control on to make it fair and when your up 2 speed, reset the mpg ang record the figures after a short while. should be abit more accurate.