Print

[Craig T]

Overtaken by Worf .... Does anybody know exactly what VW are supposed to have "claimed", to merit refunds of millions of pounds? (see current adverts on TV).

My understanding is that their engine ECU's were programmed to know when the car was undergoing an emissions test and deliberately lean the mixture to give really low emission results.
All modern cars are tested under very strict conditions in the same manner to make the tests equal so if the car ECU saw those test conditions, air temperature, air pressure, road speed, etc all matched it would default to a "hidden" program giving really bad performance but really low emissions. The chances of all these test conditions ever being met on the road during normal driving were so slim the hidden programming would never be used but it was there hidden in the depths of the ECU code....

Basically they said it was only producing so many grams of carbon per kilometre at 55mph but they weren't, they were producing much more in normal use. I'm not sure if any of their cars had to change VED brackets after the discovery of the falsified information?

Craig.

[The Shed]

My understanding is that their engine ECU's were programmed to know when the car was undergoing an emissions test and deliberately lean the mixture to give really low emission results.
All modern cars are tested under very strict conditions in the same manner to make the tests equal so if the car ECU saw those test conditions, air temperature, air pressure, road speed, etc all matched it would default to a "hidden" program giving really bad performance but really low emissions. The chances of all these test conditions ever being met on the road during normal driving were so slim the hidden programming would never be used but it was there hidden in the depths of the ECU code....

Basically they said it was only producing so many grams of carbon per kilometre at 55mph but they weren't, they were producing much more in normal use. I'm not sure if any of their cars had to change VED brackets after the discovery of the falsified information?

Craig.

Apparently the secret to the ECU knowing it was undergoing an Emission test was. The simple bonnet switch !
The ECU took readings from various engine and electrical parameters if they equaled 'x' and the bonnet was ajar then the hidden program kicked in.

[The Shed]

A couple of points in response 602. A Mercedes truck I drove some years back actually kicked your foot off the accelerator pedal at 69 MPH.
It felt like some sort of pneumatic device and no matter how hard I tried to keep it down it would force my foot up ! And why 69 ? 
That was until someone told me where to remove a certain relay. Then it really did fly ! 

When I had an SD1 Vitesse the onboard computer registered 33 MPG at 75 MPH. It's most economical. Unless you count taking your foot off the gas and watching the display run into the 000's.

There is a regular Ad' in CCW for something resembling lead pellets that makes performance improvement claims. It has been around for a while, I do wonder has it ever been tested ?

[Worf]

There is a regular Ad' in CCW for something resembling lead pellets that makes performance improvement claims. It has been around for a while, I do wonder has it ever been tested ?

According to their blurb, it was tested of Spitfires during the 2nd World War. If it was any good, you would think it would have caught on by now.

[Alan Drover]

None of the tin pellets in the tank rubbish has ever been proven beyond all doubt and late last century one company was taken to court over misleading customers (gullible idiots?) and received a hefty fine.
This RunGreen stuff is distributed from Fulham. It appears to be an American set up so I am wondering whether the ASA will be able to do anything about it. If not, it's up to us to warn drivers.

[Exile]

Remember what happened to Rudolf Diesel.

Ah yes.
He was killed by water.

Dangerous stuff.
Especially on its own.

Should always be mixed with something.....

[Wittsend]

As I posted here on 17th August .....
Ah ... that will be the old Broquet Fuel Catalyst.

Been going ages, since WWII - You put a couple of their tin pellets into the fuel tank, they are suppose to slowly "leak" away into the fuel and make up for the lack of tetra ethyl lead in the petrol.
(Tin and Lead are very closely related chemically.)

Read all about the Broquet Fuel Catalyst


 

[Alan Drover]

Most testimonials are from the Far East.  No official testing has been done by any creditable motoring organisations.

[Alan Drover]

I can remember when all these snake oil products were prolific, Practical Classics tested one in an Austin 1800 on which the cylinder head had been overhauled with new valves ground in. Just over 3,000 miles running on unleaded with tin in the tank, the cylinder head had suffered such bad valve recession, it was only got for scrap. 
Carbonflo is another one still going strong in Devon.

[ChrisJC]

When I had an SD1 Vitesse the onboard computer registered 33 MPG at 75 MPH. It's most economical. Unless you count taking your foot off the gas and watching the display run into the 000's.

It ran to 6553.5 which for a computer programmer is not a coincidence.

Chris.

[rustynuts]

It ran to 6553.5 which for a computer programmer is not a coincidence.

Chris.

Ah, the joys of two's complement. Reminds me of an article about software errors I read where a test driver of I forget which small Japanese car managed to destroy the auto gearbox of two cars upon hitting a speed the designers never thought the car would achieve: the value rolled over to zero and the controller put the gearbox into park mode.

I inherited a mesh tube containing 3 Brouquet fuel catalyst pellets which I keep in a petrol can. I never did decide whether the mower was getting more mpg for it. I guess I will never find out now I have ditched the mower for a battery powered one.

[w3526602]

Some thing came up as a "suggestion" the other day (may have been for  youtube ) along the lines of   "run your IC engine on water"  .....

Hi,

That claim may not be quite as far fetched as it first appears ... have you noticed your car runs better when it's raining?

I'm guessing that a smidgen of water turning to steam might boost the compression ratio? Or might it be that "cool" air is denser, and therefore contains more oxygen per unit of volume? Asking, coz I don't know. 

Or perhaps wet tyres on tarmac enjoy reduced friction?

The ultimate fuel economy device is the driver's right foot ... many yonks ago, I read a road test on the then newly introduced Jaguar 2.4. At a steady 30mph the fuel consumption was 30mpg, but normal driving reduced that to about 20mpg.

At Tech College, we did a "Brake" test on a Ford 10hp engine.(1172cc side valve) It drank a gallon of petrol in 20 minutes .... but it had been working very hard, probably the equivalent of flat out up a very steep hill.

602

602

602

[Ian F]

It ran to 6553.5 which for a computer programmer is not a coincidence.

Chris.

Please explain!!  I am intrigued......

Ian F

[rustynuts]

OK, if you must!

Signed fixed point integers (a fixed positive and negative numerical range) are a data type commonly represented by a notation known as two's complement https://en.wikipedia.org/wiki/Two%27s_complement.

A 17 bit variable (i.e. 17 binary digits) which must have been used in this instance, has range of 65535 to -65536. Have a play here if you wish and plug the numbers in https://www.exploringbinary.com/twos-complement-converter/. A decimal point can then be put in to any position as required, in this case one decimal place to give 6553.5

 

[Alan Drover]

I'm still non the wiser.