russellhq

I know, I know. It's not a car you buy for the ecomony but...

Is there an optimum engine speed where the stock F20C operates at peak efficiency?

I ask this because of a curious occurance that happens on two different journys. The daily drive to work, 40 min journey (13 mile) and the drive up North (190miles, lots of VTECH, motorway cruising and A-road thrashing).

The first journey I tend to keep it in high gears keeping revs low 2-4k rpm with the occasional blip of VTEC (you just can't help it!). I average about 22 mpg.

The second journey is about 2/3 fast motorway/dual carridgeway cruising (4-6k rpm) with VTEC off roundabouts etc. Then the latter part is windy A roads with low gears and overtaking. This journey averages about 28-30 mpg.

So, my question. Would driving in lower gears on the daily drive improve performace, or is the reduced figures just a result of sitting in traffic?

Bibbs

It's the stop/start that kills economy .. Don't accelerat hard or use your brakes.

I'm getting 16mpg on average to a tank, be happy with your over 20

MB

For this you need to know when the car is in closed or open loop lambda control. Open loop is where the fuelling resorts to just squirting in and regulating on pressure. Closed loop is economy mode, if you like, and uses injector pulsing.

Basically, dont put your foot down more than half way or go near VTEC, and keep it at as low rev as as you can, with the windows and roof up, tyres pumped up, and at a constant speed

Its not the sitting in traffic so much, its more the stop / start as Bibbs says below.

russellhq

I'd be happy with 16 but only 'cos I had a SC

wineboar

Sounds fun!

MB

Bibbs - you could remove that big whirly gig on the front?

Hmmm, SC with a clutch?!

Bibbs

I could, but then I'd not be as quick as a new JDM Civic

I know someone who had a Mk1 MR2 with an SC on a clutch. Made it interesting on track days where the static noise test were easily passed, but the drive bys were failed.

MB

Very Mad Max

Bibbs

Oh, and that's 16mpg commuting with no "play time".
If I'm out playing it drops dramatically.

Tempted to get a bike for the commute.

JimUK

My Passat TDI 140 only gets 30-33 most days, cos like Bibbs says, stop/start is just no good for economy. Dont even bother working out mpg for the S as its my fun car and i would feel depressed! But i bet its low teens at the best!