What causes drop in ...

[MyrtleGuru]

And pray he doesn't hit the brakes hard and suddenly

I thought the use of the smiley would be enough to tell folks I was joking...

 

[Northernraider]

I thought the use of the smiley would be enough to tell folks I was joking...

A common mistake
But smileys can also be sarcasm or smugness.

 

[Northernraider]

Call me a trainsporter but on my hymer 2.8jtd I get normal 25/26mpg
But with aircon on I'm getting more like 20/21

 

[GPW]

What can cause a sudden decrease in mpg normally attained, please?

If it's a Euro 6 then regen can reduce MPG, especially if it's smoking (intake path leaks - VW type 6's excel at those - the smoke will be internal, caught by the DPF, which has to burn it off).

Otherwise apart from the wind already mentioned the FUEL QUALITY can affect it, fill up next time at a BP/Shell/ESSO etc. if you got the poor MPG from supermarket diesel, it has been known.

 

[MyrtleGuru]

A common mistake
But smileys can also be sarcasm or smugness.

Fair enough.

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[HandyAndy]

yep fuel quality is another bow in the hat of my 68 mpg AVERAGE.... V-Power diesel for the last 15 years.

 

[Podney]

Call me a trainsporter but on my hymer 2.8jtd I get normal 25/26mpg
But with aircon on I'm getting more like 20/21

Exactly the same for me.
And I’m not a trainsporter.

 

[Podney]

yep fuel quality is another bow in the hat of my 68 mpg AVERAGE.... V-Power diesel for the last 15 years.

I’ve never heard that one.......bow in the hat. Same as feather in the cap,I guess.
68mpg! Does that include the aviation fuel you are adding,or do you stick to waste veggie oil?

 

[HandyAndy]

I’ve never heard that one.......bow in the hat. Same as feather in the cap,I guess.
68mpg! Does that include the aviation fuel you are adding,or do you stick to waste veggie oil?

nooo nothing but the purest unfiltered Shells finest for my rust bucket

 

[HandyAndy]

nooo nothing but the purest unfiltered Shells finest for my rust bucket

and all my other vehicles TBH..
I hate mother using my golf Gti, I know she's filled up from Morrisons when she's borrowed it (cos she thinks she's getting free "points")...it runs like a sack of s** afterwards. :'(

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[airwave]

Call me a trainsporter but on my hymer 2.8jtd I get normal 25/26mpg
But with aircon on I'm getting more like 20/21

Yep you probably are ! .

I heard the same statement years ago . Now it don't affect me as i never have cars with aircon or even switch it on in trucks that do . However i watched a program where this was actually put to the test . Air con verses the extra drag of having a window open . Result , leaving a window open actually used less fuel . Conclusion , Off da Grid is quite correct ! .
Now another interesting snippet from another program , again actual test . Hybrid motor , Toyota prius , following a Bmw 3 series on a test track . Bemmer was returning 30 to the gallon , anyone guess what the Prius was giving ? ,

and remember this was an actual test . By the way handy andy , i can endorse your mileage , my Citroen 1.5d tud5 is returning 72mpg . 1.4 tud3 would do even more , and for a time held the guinness world record for a standard saloon car .

 

[Podney]

and all my other vehicles TBH..
I hate mother using my golf Gti, I know she's filled up from Morrisons when she's borrowed it (cos she thinks she's getting free "points")...it runs like a sack of s** afterwards. :'(

Yes......as anybody in the know will tell you,supermarket fuel is rubbish,absolute rubbish.
No, really,supermarket fuel is to be avoided unless you can’t get to somewhere that sell the real stuff.

 

[HandyAndy]

Yes......as anybody in the know will tell you,supermarket fuel is rubbish,absolute rubbish.
No, really,supermarket fuel is to be avoided unless you can’t get to somewhere that sell the real stuff.

I know its a hotly debated topic and there are tanker drivers that say its the same fuel but I used to operate an engine dyno and have personally done back to back testing on degrees of ign advance vs detonation. So I know for a fact its bollocks.
The only fuel that i could advance the timing beyond mbt was certain race fuels at £200 odd quid a barrel.
Consistently shells optimax / v-power was top of the list in every test i did for power output.
Its not just the ron rating but the addatives. Where they get added i have no idea but i can put drop a fuel pump in shells 99 ron and advance up to the det limit then back off a few degrees for safety, then drop the fuel pump in a can of "other manufacturer 99 ron *tesco* cough and it would detonate its tits off.

 

[Northernraider]

Yep you probably are ! .

I heard the same statement years ago . Now it don't affect me as i never have cars with aircon or even switch it on in trucks that do . However i watched a program where this was actually put to the test . Air con verses the extra drag of having a window open . Result , leaving a window open actually used less fuel . Conclusion , @Off da Grid is quite correct ! .
Now another interesting snippet from another program , again actual test . Hybrid motor , Toyota prius , following a Bmw 3 series on a test track . Bemmer was returning 30 to the gallon , anyone guess what the Prius was giving ? ,

and remember this was an actual test . By the way @Handy Andy , i can endorse your mileage , my Citroen 1.5d tud5 is returning 72mpg . 1.4 tud3 would do even more , and for a time held the guinness world record for a standard saloon car .

The downside is that in the heat over here at the minute driving with the window open doesn't cool the van down neither does just the blower on as it's warm air coming in.
I'm not ususlly one that uses aircon but the last 2 months I've had to otherwise it's just too hot.
But as I've kept a record of every drop of fuel and my miles daily it's interesting to see the difference ?

 

[Podney]

I know its a hotly debated topic and there are tanker drivers that say its the same fuel but I used to operate an engine dyno and have personally done back to back testing on degrees of ign advance vs detonation. So I know for a fact its bollocks.
The only fuel that i could advance the timing beyond mbt was certain race fuels at £200 odd quid a barrel.
Consistently shells optimax / v-power was top of the list in every test i did for power output.
Its not just the ron rating but the addatives. Where they get added i have no idea but i can put drop a fuel pump in shells 99 ron and advance up to the det limit then back off a few degrees for safety, then drop the fuel pump in a can of "other manufacturer 99 ron *tesco* cough and it would detonate its tits off.

Yep,I’ve spoken to a guy in the business who knows. The additives are different and/or different quantities.
But your practical testing proves it anyway.

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[pagey]

my 875kg car is going to stop quicker than a 44,000Kg artic

only if its loaded and what about the reaction time

 

[TerryL]

I tend to always use supermarket fuel but have done my own testing, both on my diesel Peugeot 307 and the van, 130HP Ducato. From an almost empty tank I refilled with "Premium" diesel and ran it to almost empty and confirmed I was indeed getting better consumption - but the percentage increase was exactly the same as the cost increase so financially of no benefit. Exactly the same results on both vehicles.

As for the benefits of supposedly cleaner fuel, I've done over 100,000 miles in the van in 10 years with no problems (that could be attributed to the type of fuel used). I believe this is more a function of the type of driving - we tend to drive for much longer periods than the average commuter car and this must be better for the motor. Even the fuel manufacturers will tell you the additives are designed to keep the engine "clean" and thus more efficient - I've got no argument with that, it's just that my motorhome is operated differently to a car and doesn't need it.

I could also enforce this by mentioning that high-mileage cars, e.g. repmobiles, are no longer shunned as they tend to be extremely reliable.

So if you tend to do short journeys, leaving the van standing for long periods, then by all means use Premium fuel. But if you're the same as us, using the vehicle as designed (remember white van man does 100,000 miles per year) IMO it's not necessary.

I will admit, however, that when I can get discounted fuel (supermarket incentives etc) I'm not averse to "treating" my vehicles to the odd tankful!

 

[HandyAndy]

The downside is that in the heat over here at the minute driving with the window open doesn't cool the van down neither does just the blower on as it's warm air coming in.
I'm not ususlly one that uses aircon but the last 2 months I've had to otherwise it's just too hot.
But as I've kept a record of every drop of fuel and my miles daily it's interesting to see the difference ?

Hearing the other guy say just wind the window down for aircon made me laugh for the exact reason you say, you can't cool down if its baking hot air ???
Sod the fuel consumption if it's hot, I want that cabin like a god damn cool box when I'm driving. I don't like arriving to site with sweaty pits and smelling like something that crawled out of a gutter. ??

 

[GPW]

A/C power usage seems to vary a bit - I suppose it depends on implementation and settings, it affects my car more than the van for MPG - possibly because the van uses more anyway.

To save on AC switch it on when engine braking down hills and coming up to roundabouts when you want to lose speed/energy anyway.

 

[airwave]

The downside is that in the heat over here at the minute driving with the window open doesn't cool the van down neither does just the blower on as it's warm air coming in.
I'm not ususlly one that uses aircon but the last 2 months I've had to otherwise it's just too hot.
But as I've kept a record of every drop of fuel and my miles daily it's interesting to see the difference ?

Yeah , i've heard it's hot over there too mate . A mate who lives in Algodonales , is in Norfolk as we speak , does it this time every year . Clicking the low 40's as i understand it , but he has told me it's been hitting 45+ in recent years , all you can do is sit in the shade . That includes the locals , with the kids often spending the school holidays around a pool . He does tell me , it can get a little chilly later in the year though , down to 15 . Actually he's going back in a week's time , but spain is famous for it anyway , either way your right , the downside is a window you will not get the motor cool . I've got my own view's why i don't have aircon , but the fact remains , if you have it and use it , expect to pay for it .

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[Vipar]

I think you have answered you own question. Speed kills MPG. I travel at 56-60. Also if I use the M11 I get more mpg than when I do a longer journey than on the M2 because it has more and longer hills but as suggested before, change the air filter regularly especially in dry dusty conditions. I never use the higher priced derv either. I check my mpg from full tank to full tank using the same pump no good trying to work it out by guessing what you have used.

 

[bigtwin]

Now another interesting snippet from another program , again actual test . Hybrid motor , Toyota prius , following a Bmw 3 series on a test track . Bemmer was returning 30 to the gallon , anyone guess what the Prius was giving ? ,

Hardly a real world test - if I remember correctly, they were tanking around the track close to the max performance of the Prius. Hardly surprising that it didn’t perform well. If they’d been travelling at a stead 50mph the result would have been very different.

Ian

 

[Northernraider]

Yep,I’ve spoken to a guy in the business who knows. The additives are different and/or different quantities.
But your practical testing proves it anyway.

I've a mate who works at the grangemouth refinery and has done since we left school .

He claims all the superfuels are nonsense too , says no matter the tanker shell, bp whatever its the same fuel going to each garage

 

[Nirvanauk]

Letting the gap between me and the HGV in front grow to more than 6ft. Once a cyclist, always a cyclist -- tuck in behind the big guy when the wind gets up

Isn’t that a tad dangerous?

 

[HandyAndy]

Isn’t that a tad dangerous?

so is not wearing a seatbelt, smoking fags and jumping out of an aeroplane but some of us still like to do it

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[HandyAndy]

I've a mate who works at the grangemouth refinery and has done since we left school .

He claims all the superfuels are nonsense too , says no matter the tanker shell, bp whatever its the same fuel going to each garage

I have a mate who worked for Texaco (til they took his HGV licence off him for health reasons he said the same too and plenty of others I've heard say similar..
but then my det cans and piezo sensor does not lie.. Cest La Vie..

 

[2657]

my det cans and piezo sensor does not li

Qué?

 

[HandyAndy]

Qué?

ear defenders and additional electrical piezo sensor bolted to the block of an engine to detect detonation.
(uncontrolled burn of the fuel mixture) which will cause catastrophic engine failure if left unchecked..
Engine tuning and engine building was my game a number of years ago..

 

[airwave]

Hardly a real world test - if I remember correctly, they were tanking around the track close to the max performance of the Prius. Hardly surprising that it didn’t perform well. If they’d been travelling at a stead 50mph the result would have been very different.

Ian

Ya know Ian , i'm gonna let other people interested make their own mind up . It was quite a while ago , and it took a long time to find it , but ;



Oh and yes i did get the bemmer's fuel economy wrong , and i didn't realise it was an m3 either .

 

[Tony50]

Dirty air filter won’t help ?

Weight in the vehicle.

I agree check the air filter element, makes a lot of differences to fuel economy and also make sure nothing has been sucked into the air filter air supply apertures

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