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You're pulling more weight with the car, so I guess it does really.

But I do this all the time, its not very often mine is less than 3/4 full during a normal week, even going away on holidays I'm looking for a filling station if the tank is recording 1/2 full.
 

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Not unless you have a leak somewhere near the top of the tank or filler tube.

If the flap in the filler neck is not operating, "spirited" cornering can lead to spilt fuel from the filler - but Renault drivers don't do that anyway, do we? lol.:devil:
 

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Discussion Starter #4
actually i remember smelling petrol under the bonnet very close to the drivers side air grill thing. i wonder were its coming from?
 

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Primary concern, is that during hot weather the expansion of the fuel will cause it to overflow and you end up with a pool of fuel under the car!
 

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There's 3 main ways to make a car more economical, driving, streamlining and reducing weight, you can reduce the weight of your car by about 60 pounds of unnecessary fuel by only having half a tank of fuel.
 

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It all depends where you live/work. If you have to go out of your way 10 miles to fill up each time. The less times you have to do it the better
 

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I would say it is less economical to brim your fuel tank. Fuel weighs about 4lb per gallon, approx 4.5 litres to the gallon, my Lag II has a 70 litre tank, so a full tank weighs about 63lb. That is alot of weight to be pulling around with you!
 
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Does this cause poor fuel consumption if you fill it to the top?
In theory filling it would mean you carry more weight which might reduce your mpg by 2-3miles.....

I've covered best part of 750,000 miles in the last 10years & always fill whatever car I'm driving to the brim......

After all thats what the tanks for......;)
 

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It really depends on what type of driving you intend to cover, whilst filling up.

Casting your minds back to your schooldays - you'll recall talk about inertia, momentum, etc. in essence, the more mass there is to accelerate (and decelerate as well, remember), then the greater the force which is required to change velocity.

However, if the vehicle (or object) is accelerated to a constant velocity (on a level plane), then the force which is applied to maintain that speed is equal to the friction the object is experiencing (tyre & air resistance).

Quite a long-winded way to say that on the motorway - filling to the max is best (you also save on a wasteful stop, and paying higher prices), whereas for town driving, keeping it between a 1/4 and 1/2 is probably best.

Science lesson over for today - hope you were taking notes!;)

Paul:)
 
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It really depends on what type of driving you intend to cover, whilst filling up.

Casting your minds back to your schooldays - you'll recall talk about inertia, momentum, etc. in essence, the more mass there is to accelerate (and decelerate as well, remember), then the greater the force which is required to change velocity.

However, if the vehicle (or object) is accelerated to a constant velocity (on a level plane), then the force which is applied to maintain that speed is equal to the friction the object is experiencing (tyre & air resistance).

Quite a long-winded way to say that on the motorway - filling to the max is best (you also save on a wasteful stop, and paying higher prices), whereas for town driving, keeping it between a 1/4 and 1/2 is probably best.

Science lesson over for today - hope you were taking notes!;)

Paul:)
What do you say to that..............

Awesome.....................:beer:

I still brim mine though.........lol
 

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I always brim mine too, but then again, I do mostly motorway miles.

In the grand scheme of things, the difference in weight is pretty trivial. The fuel certainly weighs less than an adult passenger, and how many of us really notice a difference in fuel economy between driving alone and with a car full of people? Still, it'd help if the Lag's trip computer readout was a little more accurate - by the time you hit just over 50 MPG, the resolution has dropped to 1 MPG.
 

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I always brim mine too, but then again, I do mostly motorway miles.

In the grand scheme of things, the difference in weight is pretty trivial. The fuel certainly weighs less than an adult passenger, and how many of us really notice a difference in fuel economy between driving alone and with a car full of people? Still, it'd help if the Lag's trip computer readout was a little more accurate - by the time you hit just over 50 MPG, the resolution has dropped to 1 MPG.
I dont see why Renault couldn't do better here. My 1997 Seat Cordoba had an mpg read out that did it to the nearest 0.1 mpg, although the highest I ever saw was 42.7 coasting down a hill :rofl:
 

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side question...

when should you fill your car up then? ive always been told at 1/4 tank to stop rubbish gettin into engine..

does it really harm your engine if you take it to the petrol light or red line at least?

and does it make a difference if you fill up with v power? i.e. cleaner fuel? lol, jst sum guy i kno fills up with v power for that reason..
 

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Well, in my opinion, its a bit of an urban legend. After all, the fuel filter is there to prevent any harmful deposits reaching the engine. The fuel pickup is near the bottom of the fuel tank (naturally), so the engine (to put in aquatic terms) is a 'bottom feeder'.

However, what is more important is the accuracy of your fuel gauge (and associated computer/warning light). I would always suggest that you test this out by waiting until the tank is 3/4full, then brimming it - and comparing what went in vs what the handbook says a 1/4 tank should be. Repeat this at 1/2full and 1/4full, to get a broad picture.

If you notice the guage gets less accurate with less fuel in the tank - either replace the sender unit; don't let the fuel level stray much below; carry a spare gallon in the boot.

Just remember though - letting an engine run dry isn't a good idea as (especially in diesels), the fuel acts as a lubricant for the fuel pump - and any air in the system needs to be 'bled'.

As for different fuels - I would always choose a 'branded' fuel over a supermarket supplier - just look at theTesco/Morrisons fiasco if you need convincing - the costs aren't much different if you shop around. As for 'enhanced' fuels - well, I personally think an occasional tank will probably do some good (as would a suitable fuel additive), but unless your car's ecu can adjust for the octane levels or its recommended (i.e. FSI engines), then it probably won't be of long-term benefit for continuous use.

In my opinion, for 'regular' cars - one tank of the premium stuff every 4th/5th tank would give the benefits.

But bear in mind its no substitute for regular servicing, and a regime of preventative maintenance.

Paul:)
 

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Renault recommend that you refuel ASAP after the low fuel warning light comes on. I think that's also their half-baked excuse for losing the range on the trip computer once the warning light comes on.

Keeping 1/4 of a tank might well be a good idea in an older car with a steel fuel tank. If the tank has rusted on the inside, then flakes of rust may well have collected in the bottom. Drain the tank too low, and you'll drag the rust fragments into the fuel line.

But most modern cars have plastic tanks, so that should no longer be an issue. If you run them completely dry, then a little bit of sediment might just find its way into the filter and, if you're really unlucky, block it. I've run most of my petrol cars dry at one point, and only one of them ever complained (one of my Lag 1's.) It ran like a sack of spuds for the rest of the day, but sorted itself out after a while.
 
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