Does better MPG means better fuel?

CiniO

I tent to fill up my diesel car in one particular station around my area. For normal driving around I usually get around 6 l/100km.
But whenever I fill up anywhere else, I end up with about 6.5 up to 7 l/100km (so considerably worse).

Does that mean that on this one particular petrol station quality of diesel is good and everywhere else it's crap, or can there be any other reason?

Foxhole Norman

I wouldn't consider .5/1l difference enough to judge fuel. 3-6 MPG drop wouldn't be able to discern bad fuel, that could be caused by a multitude of variables. Now, if you were doing maybe 7/8l/100km I may look at it as dodgy fuel.

CiniO

Foxhole Norman wrote: »

I wouldn't consider .5/1l difference enough to judge fuel. 3-6 MPG drop wouldn't be able to discern bad fuel, that could be caused by a multitude of variables. Now, if you were doing maybe 7/8l/100km I may look at it as dodgy fuel.

Well I'm not saying that fuel on every station except the one I mentioned is dodgy.
I'm just curious what could be the reason for 0.5 to 1 litre/100km difference on one particular petrol station?

And just to mention measurements are not just an odd ones - I've been keeping track for the last 2 years.

CJ Haughey

I never fill up the tank, extra ballast does not help your mpg. Differences in mpg with different petrol stations is down to where they get it from.

CiniO

CJ Haughey wrote: »

I never fill up the tank, extra ballast does not help your mpg.

My full tank is 45 litres, which equals to about 37 kg.
I don't believe this makes any noticeable difference in car weighting over 1400kg.

Differences in mpg with different petrol stations is down to where they get it from.

But is there a simple dependency that better the MPG the better the fuel, or is there more to that than this?

faral

CJ Haughey wrote: »

I never fill up the tank, extra ballast does not help your mpg. Differences in mpg with different petrol stations is down to where they get it from.

AFAIK all stations get fuel from Whitegate rafinery

CJ Haughey

CiniO wrote: »

My full tank is 45 litres, which equals to about 37 kg.
I don't believe this makes any noticeable difference in car weighting over 1400kg.

My tank is double yours in volume so carrying around an extra 37kg for half a tank would have perfomance difference.

But is there a simple dependency that better the MPG the better the fuel, or is there more to that than this?

I cannot answer that, all i know is i know where to get good fuel locally and where to avoid.

ozmo

Dunno - but...

? Was there a difference in the locations where you were using the petrol?(heaver traffic)

? if your calculations are based not on a built in car fuel usage computer but on filling the tank and seeing how far you get - are you sure the tank was filled at the same point exactly on each test?

? could your "good" station is giving out too much fuel by mistake for the price?

CiniO

ozmo wrote: »

Dunno - but...

? Was there a difference in the locations where you were using the petrol?(heaver traffic)

No.. I refer to local stations when I drive locally (work commute, shops, etc...)
Driving style and conditions are nearly always the same.
I mostly fill up at this one petrol station, but when I fill up somewhere else, I always get worse MPG.

? if your calculations are based not on a built in car fuel usage computer but on filling the tank and seeing how far you get - are you sure the tank was filled at the same point exactly on each test?

Yes - always to the same point. You can actually see diesel level when you fill up the tank it's just below the cap.

? could your "good" station is giving out too much fuel by mistake for the price?

Over last 2 years? I don't think so.
Besides if they did, it would show smaller fuel consumption on previous tank (which could be filled up somewhere else) so it's definitely not the case.

ozmo

CiniO wrote: »

No.. I refer to local stations when I drive locally (work commute, shops, etc...)
Driving style and conditions are nearly always the same.
I mostly fill up at this one petrol station, but when I fill up somewhere else, I always get worse MPG.

Sounds like you found a garage with a consistent high octane rated fuel - stick with them so

CiniO

ozmo wrote: »

Sounds like you found a garage with a consistent high octane rated fuel - stick with them so

It's diesel I'm using- so no octane rating.
And even if it was petrol, octane rating would have hardly any effect on fuel consumption.

ozmo

CiniO wrote: »

It's diesel I'm using- so no octane rating.
And even if it was petrol, octane rating would have hardly any effect on fuel consumption.

Oh cetane or whatever the thing to look out for in diesels is called.



"with inconsistencies in cetane ratings at the pump, many diesel owners experience fluctuating fuel mileage."

Read more: http://www.dieselpowermag.com/tech/ford/0911dp_fuel_additive_test/#ixzz3T6RO55oj

Bandara

No

It doesn't at all

Jesus.

Foxhole Norman wrote: »

I wouldn't consider .5/1l difference enough to judge fuel.

It was a .75/1l difference he said

Foxhole Norman

CiniO wrote: »

I usually get around 6 l/100km.
But whenever I fill up anywhere else, I end up with about 6.5 up to 7 l/100km (so considerably worse).

Jesus. wrote: »

It was a .75/1l difference he said

.

Jesus.

That's a .75 difference lad (between half and one)

Foxhole Norman

Jesus. wrote: »

That's a .75 difference lad (between half and one)

He never said between

He also states himself, 0.5 to 1l.

Jesus.

Indeed but you took the first amount and disregarded the second

The average is .75

Foxhole Norman

OK.

CiniO

Jesus. wrote: »

Indeed but you took the first amount and disregarded the second

The average is .75

Foxhole Norman wrote: »

OK.

Great.
Now when we all established, that my fuel consumption is best from one particular station, and on every other station it's on average worse by 0.75 l/100km - what can be the reason for that?

It would be perfectly simple if it was otherwise. If fuel from one certain petrol station gave worse fuel economy figure, then it would probably mean that fuel from there is of bad quality.

But it's hard for me to imagine why is it opposite. Does that mean that fuel everywhere is crap, except from that one station I fill up usually?

pippip

When you say a different station are you talking a different brand or same brand but different station?

Dartz

As a percentage of consumption, it's a fairly significant amount....

****, I filled up on Maxol down in Cork.... it used 35-36L on the way up. Compared to 40 litres of Topaz on the way down - under the same loading conditions.

pa990

Dartz wrote: »

As a percentage of consumption, it's a fairly significant amount....

****, I filled up on Maxol down in Cork.... it used 35-36L on the way up. Compared to 40 litres of Topaz on the way down - under the same loading conditions.

Wind ?

Jesus.

Dartz wrote: »

****, I filled up on Maxol down in Cork.... it used 35-36L on the way up. Compared to 40 litres of Topaz on the way down - under the same loading conditions.

Ah but you were going uphill on the way up

Foxhole Norman

Jesus. wrote: »

Ah but you were going uphill on the way up

He used 40L on the way down to Cork, downhill and 35L uphill to Dublin, my understanding anyway.