ScoobyNet.com - Subaru Enthusiast Forum

ScoobyNet.com - Subaru Enthusiast Forum (https://www.scoobynet.com/)
-   General Technical (https://www.scoobynet.com/general-technical-10/)
-   -   Decat & Dawes = Shocking mpg? (https://www.scoobynet.com/general-technical-10/128199-decat-and-dawes-shocking-mpg.html)

Neanderthal 03 September 2002 06:55 PM

Hi all,

I've got an MY97 and have recently fitted a Dawes (now running at 15psi) and have a full decat exhaust system.

I've now got the performance I was after but the miles I get to a tank of petrol seem to be getting fewer and fewer. Now some of this will be down to me "enjoying" the power & changing where I work which is now only a 3 mile drive compared to the 11 mile drive I had to do before. I've gone from a usual 260 miles per tank to 230 (new place of work pre mods) to 180 to a tank. Is this drop normal? Do decat exhausts make the Scooby burn more fuel? does the Dawes? or has my right foot become to heavy?

Matt

Brun 03 September 2002 06:58 PM

I think my decat has lost me about 1mpg.

snowcrash 03 September 2002 07:03 PM

my de-cat and dawes has meant my fuel top up's are now every 210miles rather than 240-250miles.. :(

but she's a tad quicker now :D

ScoobyJawa 03 September 2002 09:49 PM

I got 17mpg when I fitted the Dawes with a decat :eek:

gene1 03 September 2002 10:15 PM

Recently fitted full de-cat and blitz sus and no different at all on fuel.Have had loads of hi-performance cars and always thort the Quattro ur Turbos returned good fuel to performance,but must take my hat off to the Scoobys its excellent on petrol considered what it returns in power.
Gene

dnb 03 September 2002 10:30 PM

Very short journeys always seem to use more petrol. You strike the car up more times per tank full, and IIIRC the car runs a bit rich when you first stike it up - and the idle is higher until it is warm (only briefly). All these little extra bits add up though ;)


paulwadams_my99 03 September 2002 10:56 PM

interesting that most of you notice no difference in the positive side of a decat? I got an extra 20 miles to the tank at least with full decat. :)

LG John 04 September 2002 09:55 AM

I would have thought that, strickly speaking, a decat will improve fuel economy as the engine can opperate more efficienly without the restrictive cats. With the downpipe the turbo spools up earlier so your probably on boost more. I think you'll notice an improvement if you have the right foot of a saint when wanting to drive normally :D

bioforger 04 September 2002 10:04 AM

The scoobs fuel effiency isnt designed for short trips, anythin below 10mile trips, n u can say hello to 18mpg all the time. Add a bit of motorway and its a different story.

Pavlo 04 September 2002 10:35 AM

heavy right foot = shocking mpg

You can be very gentle with the go pedal, troulbe is when you have more power, you tend to just accelerate more quickly even though you're not flooring it. For instance I can get 10psi at 3/4 throttle, which is max standard boost. So while not flooring it, I can be using the same fuel as a stand car that would be flooring it, if that makes any sense.

Paul


All times are GMT +1. The time now is 03:07 PM.


© 2024 MH Sub I, LLC dba Internet Brands