Nice comparison EB! :thumbs:

Why would lights on make too much difference

 

Slightly off-topic, but hey...

There was due to be eurowide legislation coming into force last year that all new cars should be set up to drive with headlights on all the time and that all cars should drive with them on from 2009/10. Then the green lobby said that in spite of the proven improvement in safety (estimated at 11% reduction in daytime collisions and 3-5% reduction in fatalities), this would increase fuel costs. So Volvo did some calculations and discovered that the resultant increase in fuel consumption would amount to less than £1 per year for the average driver, even at today's prices. In spite of this, the proposals seem to have been shelved. However, some manufacturers (ie Volvo, Saab, BMW & Audi) have decided that they would like to keep more of their drivers alive to be able to buy another car later and so have set up their cars with daytime running lights. Alfa, among others, have taken the middle ground by allowing headlights to stay on permanently if required and switch off automatically when the engine goes off (as opposed to staying on and buzzing at you).

Btw, if you see a black 159 with its headlights on on a bright sunny day, it may well be me - hang the expense!

 

Ive read that by turning off as many electrical items as possible you can cut the consumption, but I didnt notice any difference.

 

The more power an engine develops a less percentage amount of the power is used to drive the alternator. Consequently if you had an 1100cc car with aircon, you would even notice a loss of power with it on, let alone fuel consumption.

 

That's a megga figure. I got 34.8 once over 52 mainly motorway miles at 75mph. The 1.9 159 loaner I have did the same journey at 36mpg. Not viable at all.

 

33mpg everyday - can get 38 on a long motorway run - thats in a 2.4 q4 sw! feeling happy that i didnt go for the 1.9 now!

 

Computer says have averaged 27.6 mpg for the first 1000 miles. Driven like an old woman, but lots of town mles at least 60%

 

Sounds about right, town driving kills the mpg. The pose factor makes it worth while though...

 

Euroboy - was that with the roof up then?

 

I'm pretty sure the lights at a couple of hundred watts isn't going to make any difference but the aircon unit can eat up several thousand watts depending on how hard it's having to work. Even so I've never noticed any perceivable difference with it on or off so it just stays on.

I reckon the biggest saving depends on how just you drive. I quite often get up in the mid thirty's on a long motorway journey which is good for the pocket but makes for a boring ride. Sticking it on cruise at just over 70 which I do a lot of, I'd normally expect to average about 32 which isn't too bad and not a lot less than a lot of 2.4 owners report.

One time I thought I’d test the maximum economy that could be achieved. I drove from Barrow in Furness to the M6 (about 25 miles) on quiet roads using an incredibly light right foot. Can’t remember the exact figure but it was a tad over the 40 mark.:wow:

 

Yes roof up. The climate control makes a definite and big difference to the mpg figures. I still have it on all the time though

 

Just back from a Grand Tour to northern Spain. Just under 3000 miles avg. consumption 22.1mpg.

Mostly roof down, air con off, with the Spyder boot rack and suitcase attached. Fairly modest motorway cruising on the way down 80mph ish, though did boot it a fair bit through France on the way back 100-110mph for long stretches (was worried about the rack coming off)

Adey

 

Roof down doesn't seem to make much difference to me (even with Aircon on as well). On my weekly trek to Geneva Airport and back (120 miles @ 120kph) I've now got it down to a fine art to hit over 50mpg - I don't then feel too guilty at giving her a good thrashing on the way to the office on weekdays.