C280 - 16.8mpg !!

[iscaboy]

Generally speaking, you can get around 3% better mpg from a manual petrol than an auto, and 5% better mpg from a manual diesel than an auto.

With a manual diesel of course you do not need a fixed fuel air ratio, so you can have a wide range of fuel usage per cylinder stroke, from bare tickover to cuffing it with excess fuel.

The real secret is not wasting energy, eg mass of vehicle x velocity of vehicle.

Find a nice quiet bit of flat surface, maybe an empty car park, pick an object / marker, put a marker out, then walk in a line an put another marker where you think the car will coast to and put your second marker.

Then do it in the car, get up to 10 mph (5mph if you can see it on your speedo) and as soon as you pass the marker going straight take your feet away from the pedals and shift into neutral (manual or auto, you can shift to neutral in an auto an tickover rpm and 10 mph or less, never shift into gear though) and see how far you go.

Racing drivers often pick a similar place but with a small slope, then just coast from a mark, repeat 20 or 30 times working your way through a range of tyre pressures (and of course tyre types) again, an astonishing range of variation.

NB

I am NOT talking about hypermiling or other dangerous driving techniques.

I AM talking about advanced driving techniques, plot a course down the road, obey ALL the regulations, and run the course with the minimum number of control inputs, and with each input itself the minimum amount (eg smallest steering wheel deflection, smallest braking, smallest acceleration).


You HAVE to read the road ahead to do this.

Positive benefits.

1. You will become a much safer driver, and other road users will find it much easier to "read" your intentions.
2. You will reduce your fuel consumption dramatically, 25-50%
3. You will reduce brake / clutch / tyre wear dramatically, 300% or more
4. You will reduce mechanical wear and tear dramatically, 1000% or more
5. Your journey times will AT WORST be the same, probably be shorter (lights in a 30 zone are usually timed to 25mph)
6. You will never get a fine or endorsement.
7. You DRAMATICALLY (orders of magnitude) reduce your chances of being involved in an RTA.

(in the spirit of full disclosure, I used to teach limo driving, forget all the "escape from the gunmen" crap, limo driving is actually about staying smooth while always maximising your options, for example if you drive like most people in rush hour you can't see road between you and the car in front, you now have to ram and damage your vehicle to get out, sound silly? well it applies once every week or two when you have to make way for an emergency vehicle, and everyone else has to kerb their wheels or sit there like an idiot)

 

[BlackC55]

In city traffic, you never, ever, ever, ever, need more than 1,500 RPM, this is as true of an auto box as a manual. Braking should be equally light and gentle.

Now re-define your "not that heavy footed" in the light of the above.... I suspect I could drive your car on the same route, make the same schedule, and get as a minimum 50% more mpg, maybe even 100% more.

I tried that today at 1500RPM my car is doing 25 mph. I do like to go a little faster.

 

[BlackC55]

I enjoy driving.

Boring?

If I want excitement in my life the most boring place to look for it is behind the wheel of a car on a public highway. Without wishing to be insulting I can think of nothing sadder than having to resort to driving a car on a public highway for excitement.... over half the population is female you know...

I don't have a catalyst, or under bonnet electronics, or anything else..

I should have taken a picture of my intake manifold last week, clean as a whistle, I did more or less have pictures of my exhaust manifold, a very light coating of soot, no more than paint thickness, that'll do me.

I get great pleasure in blasting my V8 up the motorway and around the twisties. Bollock*s to the fuel economy, I'm having fun. It is not the most exitement in my life just small proportion of it. I drive a 4.3L C-class and not a DERV because I ENJOY IT. It makes me feel good. If I want to go really fast I get out on the track, which I do once a month or more.

 

[iscaboy]

I tried that today at 1500RPM my car is doing 25 mph. I do like to go a little faster.

25 is reasonable in a 30 limit in a city.

trying to go faster often just bunches the traffic and causes stop start traffic, phantom jams etc.

 

[BlackC55]

I suspose it depends on the city