Couple of questions

Brallaqueen

I have a 63 plate Seat Mii Toca. It is a small 1.0 litre engine and manual gear.

Is there any detriment/benefit to filling up from warning light to brim versus topping up on a weekly basis?

Can i improve my mpg? It is about 40mpg at the moment as per an online calc which sounds a bit crap. My driving is in-town and short journeys involving stop start, with a bit of dual carriageway to work.

I have been driving less than 2 years so not a lot of experience

Netwizard

Brallaqueen wrote: »

Can i improve my mpg? It is about 40mpg at the moment as per an online calc which sounds a bit crap. My driving is in-town and short journeys involving stop start, with a bit of dual carriageway to work.

Start / Stop and town driving is the worst sort of driving for mpg. 40mpg sounds pretty amazing actually (to compare, my car does 15mpg with this sort of driving!) so I would say you are doing just fine.

In terms of filling up or just sticking £10 each week. Never understood why you wouldn't brim it. It means less time spent at the petrol station!

Sticking £10 in a time just means you have to spend more time at the petrol station, which personally, is a place i try to spend as little time as possible in!

fivetide

I go red light to brim each time.

Fuel does go off over time so fresh stuff is good. Plus, you'll find it easier to measure your mpg doing it that way.

In an MSE manner, Esso regularly do days with 2p a litre off fuel. Worth filling up then as you'll only have to go back and top up a few days later at a higher price otherwise.

Generally, prices tend to keep climbing rather than fall anyway.

AdrianC

Brallaqueen wrote: »

Is there any detriment/benefit to filling up from warning light to brim versus topping up on a weekly basis?

Can i improve my mpg?

The only possible benefit would be down to weight saving. Except that your car has a 35 litre fuel tank. Petrol weighs about 750g/litre, so even a full-to-the-brim tank only contains 25kg or so. Considering the whole car weighs about 1100kg, you can see how big a difference that'll realistically make.

Fuel economy is _ALL_ about driving style and conditions.

Brallaqueen

That's great, thank you all for sharing your knowledge. I am not very car savvy so this forum and you, the posters, are invaluable!

Netwizard, I hate petrol stations so good point
fivetide, thanks for the Esso tip I'll keep an eye out!
AdrianC - ca you expand on driving style a bit more? I admit to revving the hell on the DC but that's partly to get up to speed compared to more powerful cars.

AdrianC

Brallaqueen wrote: »

AdrianC - ca you expand on driving style a bit more? I admit to revving the hell on the DC but that's partly to get up to speed compared to more powerful cars.

Not easily in text. Either book a post-test session with a driving instructor or find out about your local IAM, and do some sessions with an observer. Not only will you drive more smoothly, and use less fuel, but you'll drive in a safer way, too.

There's a slightly over-simplified, but basically true, saying - "the right pedal uses fuel, the middle pedal wastes fuel".

Mr_Mink

I have a bit of good news for you. I have had the sister car (VW Up) for approaching a fair while now and have noticed that the fuel economy on the car drops quite a bit over winter. Each winter my car goes down to about 54 mpg. By the time summer is in full swing the little car is pulling 62 mpg and that's with air-con on continuously. So I'd imagine you'll be seeing an upturn in your economy figure soon.

iolanthe07

A 63 plate is a new car and you will find that your fuel economy will improve as the engine loosens up with use.

Joe_Horner

AdrianC wrote: »

There's a slightly over-simplified, but basically true, saying - "the right pedal uses fuel, the middle pedal wastes fuel".

Pretty much this.

Accelerating hard might use extra fuel (depending on the car to some extent), but nothing like as much as braking hard.

When you accelerate you're turning the chemical energy of the petrol into kinetic energy of the car. In a perfect world, it wouldn't matter at all whether you accelerated hard for a short time, or more gently for longer, because you're still adding the same amount of energy to the car. Things like mechanical efficiency and air resistance get in the way of that perfect world, but not by much.

A 1000 kg car travelling at 100kph (62mph) has a total kinetic energy equivalent to the energy you'd get by burning about a teaspoon of petrol allowing for typical efficiencies. So, in order to accelerate from stopped to 60mph, yoou'll burn about a teaspoonful of fuel.

When you brake, you're turning useful kinetic energy (from the car's speed) into useless heat energy at the brakes.

Imagine your car is doing 60mph as above and you let your foot off the throttle and coast to a stop. Your "teaspoon worth of fuel" that you burnt getting up to speed might let you continue rolling for another half a mile or so.

If, instead of coasting all the way (which is rarely practical), you plan ahead and brake gently, then that teaspoon might only take you 1/4 mile - about 400 metres..

On the other hand, if you do a full emergency stop then, using Highway Code figures, that teaspoon will only take you 55 metres.

The more you brake "late and hard", the closer you're getting to that emergency stop each time. Every time you do that you're throwing away distance that you've already "paid for" in fuel used when you accelerated. You then need to use even more in order to accelerate again.

So, think ahead, try to brake early and lightly, and watch your consumption improve!

jaydeeuk1

fivetide wrote: »

Fuel does go off over time so fresh stuff is good

Petrol/diesel is over 100 million years old, not sure an extra month or two will make much difference.

AdrianC

jaydeeuk1 wrote: »

Petrol/diesel is over 100 million years old, not sure an extra month or two will make much difference.

The crude oil might be millions of years old, but the aromatic hydrocarbon chains and the additive packages are a bit more volatile than that was.