Petrol what's the most economical way to fill the car?

wannabeasupersaver

Hi all. Just wondering what others think the best way of filling the car is. I have a car that takes about £70 to fill it up completely. I have been completely filling it, running it down then putting a full tank back in. I've begun to wonder if this is the most economical way to do this. I'm i best to do what I've been doing or better filling up in smaller instalments? What do others think? Thanks x

notanewuser

Won't make any difference whether you do 1x£70 or 7x£10 provided your driving style remains consistent. If you drive less economically because the needle is high up the fuel dial then you'll use more fuel.

RichardD1970

You may make a slight saving not filling to full (everything else being equal) as there will be less weight in the car, but if you have to go out of your way at all to fill up 10 times instead of 1, any saving you would make would be lost.

neilmcl

As above, no difference at all. It's not how you fill up but what you do in the intervening period that effects your fuel economy.

wannabeasupersaver

Thanks everyone :-)

RichardD1970

Although saying that the advice on the MSE site is that it is more efficient.

http://www.moneysavingexpert.com/travel/cheaper-fuel

Joe_Horner

neilmcl wrote: »

As above, no difference at all. It's not how you fill up but what you do in the intervening period that effects your fuel economy.

This. Even the extra weight will make very little difference if your driving style is economic. It uses more petrol to accelerate the extra weight, or to pull it up hills, but you then save virtually the same amount as you slow or go down hill again unless you're using your brakes.

As an idea of how little difference it can make, we trailered a car up from Essex to North Wales last year. On the run down with an empty trailer we averaged just under 40mpg, on the way back with an extra 800kg on board (and more air resistance) we averaged just over 38mpg.

On that basis, 30 or so kg of extra fuel really isn't going to make a difference!

david39

Keep your eye on the trend in petrol prices.

If the price is persistently rising, fill the tank to the top because next week a fill will probably cost you more per litre.

If the price is falling each week, just buy small amounts. Chances are that next week you will pay less per litre.

In the last few weeks, I have saved quite a few pence per litre by adopting this strategy in a market that has fallen almost every week during November and December but it does not work if you are a heavy user filling up each day.

vaio

Joe_Horner wrote: »

......As an idea of how little difference it can make, we trailered a car up from Essex to North Wales last year. On the run down with an empty trailer we averaged just under 40mpg, on the way back with an extra 800kg on board (and more air resistance) we averaged just over 38mpg......

Surely N Wales to Essex is generally down hill so to make your example valid you'd need to repeat the journey and return the car to whence it came

Dave_C_2

david39 wrote: »

Keep your eye on the trend in petrol prices.

If the price is persistently rising, fill the tank to the top because next week a fill will probably cost you more per litre.

If the price is falling each week, just buy small amounts. Chances are that next week you will pay less per litre.

In the last few weeks, I have saved quite a few pence per litre by adopting this strategy in a market that has fallen almost every week during November and December but it does not work if you are a heavy user filling up each day.

I fill up every six weeks or so (retired so no daily commute)
Trying this method lately has proved to me that I can't predict the future! Every time I fill up the prices then come down, only to rise before the next fill.:(

Tesco 5p off per litre helps mitigate this.

Dave

Joe_Horner

vaio wrote: »

Surely N Wales to Essex is generally down hill so to make your example valid you'd need to repeat the journey and return the car to whence it came

Damn, didn't think of that! On the other hand, that means we were pulling the loaded trailer uphill so adding that weight probably made it more economical

Curiously, towing a trailer tent with my old Triumph 1300 was more economical than not towing because their economy dropped off very sharply above about 55 - 60 mph. The trailer slowing it down more than compensated for the extra weight with that one