Omega Owners Forum

Chat Area => General Discussion Area => Topic started by: JamesV6CDX on 27 October 2007, 01:47:55

Title: MPGs seem lower since clutch change
Post by: JamesV6CDX on 27 October 2007, 01:47:55

Did a test last night, filled up, drove down to Cardiff (giving it some welly mind)... filled back up, and worked out my average MPG to be 20.5.

Did a test today, filled up to the top, did some running around.

Covered 32.6 miles. Filled back up at the same pump, and it cost £6.20.

I worked out the MPG to be 24.35. This was a combination of careful town and A road driving.

To be honest, I used to get 31mpg under these conditions.

I can't think it's anything related to the clutch change - the only things I disturbed were the lambda's.. but I can't see that causing too much of an issue, as they are connected back up.

Only other observation, is that I'm using the loopy juice (Esso premuim petrol) instead of normal 95ron.. and I recon the higher octane stuff is less economical in my car.

Thoughts welcome

Title: Re: MPGs seem lower since clutch change
Post by: TheBoy on 27 October 2007, 17:57:32

Booting it more?

Title: Re: MPGs seem lower since clutch change
Post by: JamesV6CDX on 27 October 2007, 18:38:44

Just did about 70 miles, MID reads 30.3mpg, mixture of 65mph motorway, heavy traffic, and then 80mph motorway.

I'll go top it back up in a bit, and see how much it takes...

Title: Re: MPGs seem lower since clutch change
Post by: JamesV6CDX on 27 October 2007, 19:56:41

Quote

Just did about 70 miles, MID reads 30.3mpg, mixture of 65mph motorway, heavy traffic, and then 80mph motorway.

I'll go top it back up in a bit, and see how much it takes...

When I got to the garage, the MID read 30.2mpg - but the actual MPG was closer to 35...

Title: Re: MPGs seem lower since clutch change
Post by: Omegatoy on 27 October 2007, 19:57:44

thought you fitted a new exhaust as well? if so the differnce could well be the new exhaust running the lambda full rich cos of the extra flow, give it a couple hundred miles and it will get better mate :y

Title: Re: MPGs seem lower since clutch change
Post by: Chopsdad on 27 October 2007, 20:30:42

Never used Esso loopy juice but I get extra mpg with BP Ultimate, but less with Shell Optimax.

Title: Re: MPGs seem lower since clutch change
Post by: Tony H on 27 October 2007, 21:11:12

General consensus of opinion is that higher octain fuels return better mpg, but I think that the jury is still out.

Title: Re: MPGs seem lower since clutch change
Post by: ffcgary1 on 27 October 2007, 21:21:05

Have been up to stevenage today, and i reset the comp when i got on to the M25, and put cruise on at 70 mph, left the A1 at J7 and the computer was saying 40.4 mpg. On the return journey at 70mph and including the journey through south london to Mitcham it showed a combined mpg of 34.5. Well pleased overall with that. :y :)

Title: Re: MPGs seem lower since clutch change
Post by: justme on 27 October 2007, 22:11:56

Quote

General consensus of opinion is that higher octain fuels return better mpg, but I think that the jury is still out.

Shoulnt be it is fact, in any event your mixture is altered to suit the fuel. The danger being using the cheapo
fuel and trying to get the performance whilst booting it  = pre-ignition = detonation = hole in piston = naggered engine.

Title: Re: MPGs seem lower since clutch change
Post by: Paul M on 28 October 2007, 18:14:33

Quote

Quote

General consensus of opinion is that higher octain fuels return better mpg, but I think that the jury is still out.

Shoulnt be it is fact, in any event your mixture is altered to suit the fuel. The danger being using the cheapo
fuel and trying to get the performance whilst booting it  = pre-ignition = detonation = hole in piston = naggered engine.

Nope the engine has knock sensors to detect det, so it retards the ignition as appropriate. It's for this reason that higher octane fuel can give better economy as the ECU can run more advance on the ignition. Depends on the engine/ECU.

I definitely noticed more of a difference on my Impreza, but turbocharged engines are more prone to det on crappy fuel so not surprising really.