Hypermiling - best base car..?!

[benlovesgoddess]

I bought a new Hyundai i20 Blue Drive 1.1 Crdi a year and a half ago, as it had the highest official MPG fuel figures of any car we looked at (anything dinkier, Ford Ka, Smart etc...were banned). As it turns out, the official figures are an absolute joke - they may as well have said the car dispenses a £20 note from the glovebox whenever you fill up, as an equivalent lie to trick me into buying one. Anyway, bitterness aside, surely this car would be the perfect starting point to tweak the engine, apply aerodynamics and use driving techniques to get the best MPG from? 94 was claimed extra urban, I'm getting around 60 on extra urban. UK car sales of this model were miniscule, but does anyone know of an MPG geek who has one and is currently rebuilding it in secret as the ultimate hypermiler....anyone thinking of using one as a starting point....?!
What is the best base car currently for hypermiling - Prius or other hybrid, small diesel or petrol microcar?

[Draigflag]

As mentioned numerous times on the Web and various forums, the NEDC test cycle as used to obtain emission and fuel data is open to manipulation and manufatures use this to their advantage. Did you know they preprograme the cars ecu so that it knows it's on a test, and therefore uses even less fuel? Having said that, there is a group of people who get together once a year and compete in the MPG marathon. They prove that these silly figures we see time after time are achievable with a lot of hard work, alot more than most people are willing to do everyday! Some even managed almost 100 MPG in a Honda Estate diesel, not especially famous for its economy.

Anyway, if you want better economy in yours, and are willing to compromise on comfort, safety etc etc, then you could start stripping the car down, removing any unnecessary weight etc, and/or get an ecu remap, plenty of tuning companies offer eco maps for most cars ecu's now. I might have mine ecomapped when the warranty expires.

[trollbait]

The NEDC is also really light on the accelerator. Accelerate slower than a little old man in order drive its test cycles.

[benlovesgoddess]

Well, we are both dieting...plus I could clear the boot out (only badminton stuff & cleaning kit usually), but the rear seats do get used now and then so they better stay. I did not know the car knew it was on a test, but I assumed they sent a specially rigged car for that! As for the remap, I'm game - if there is a proven result. I'm talking with someone trialling a remap on my model, but it's not going well.
Sadly I have may hills, so I have to use pretty brisk acceleration more often than I'd like.
I posted this as I see my model as having great potential for being a hypermiling champion- if anyone out there with one has had a successful eco remap, then I'd gladly follow suit. Currently my MPG seems pretty random, I wonder if the car has a fault in the ECU.

[Draigflag]

Do you do a lot of short journeys in built up areas? That's what kills my economy, and no doubt most people raising questions similar to yours. An engine is at its most efficient when all the fluids have warmed up fully, which can take a bit of time. My car is similar to yours in size and similar engine etc and I understand what you mean, but if you hypermile or can be bothered to, you would probably get 90 to 100 MPG. It would near impossible to maintain that over a tankful though, my patience would dry up after about 30 miles! I too have a lot of hills here in Wales, munches through the fuel on the way up, but remember to take advantage going down the other side by letting the car coast in neutral, building up speed then trying to maintain that speed. That's what I do anyhow.

[benlovesgoddess]

Most of my journeys are 16 miles or more, with only trace city miles (but them damn hills!).
I have recently experimented with coasting...previously I've not used it, due to both the feeling of not being in control, and the mixed reports of whether or not it actually saves fuel.
There is definitely an excellent feeling as a decent incline sends it rolling away without engine braking, but I can't tell if its using less diesel...
I coast with the clutch depressed, but the correct gear selected ready to re-engage.
Are you saying it needs to be in neutral to gain a fuel saving bonus?

[Draigflag]

Well putting the clutch in does put the car in neutral anyway, it's the same thing, but like you say, probably best leave it in gear for if the car gathers too much speed. I know the engine uses no fuel when coasting in gear, but the thing is, the car speeds up quicker, and travels faster, and therefore longer without the need the accelerate again when not in gear. I just feel engine braking slows the car too much, so you have accelerate sooner when you reach level ground again.

[OliverGT]

Do you have an MPG guage in the car?

Most cars have these nowadays, ideally you want to be using the instantaneous one most of the time, this will tell you what kind of driving is using the least fuel.

For the hills, you need to be gaining speed on the downhill part and slowing down on the uphil part. Speed limits and safety permitting.

Only coast in Neutral if you feel safe doing it. I use that technique on certain parts of my journey, but only when the roads are dry. Any rain or signs of ice/snow, I always keep the engine connected to the wheels, it's much safer.

For Diesels, accelarating slowly is the key.

Keep us posted on how you get on.

Oliver.

[daver277]

Velocity slaughters fuel economy. The energy required to push an object through air increases exponentally
I view coasting downhill and gaining velocity as an energy storage device to be consumed going up the nexthill. V squared/2g is your velocity head which translated into the vertical distance the velocity willtake you.

[benlovesgoddess]

Curse these Yorkshire Wolds - beautiful but costly...! I got a personal best MPG, by staying on the level ground. 85.97 MPG from 282 miles of mostly motorway, mostly 56 mph. Junction closures meant I lost 70 miles of motorway to A roads with roundabouts, and about a third of the journey was 50 mph limit, so had to drop from 56 mph (which is the best economy speed, right?!). I had my son in the car, and a boot full of holiday luggage, plus a full tank (obviously, to work out MPG for the trip). 3 pit stops, and some overtaking at 60 - 70 mph, to be able to maintain 56 mph.
My next full tank will probably be back to sub 60 mpg, as it's hills, hills, hills again!
Could I have achieved over 90 MPG without the bad luck...?!