When the emissions are checked for the MoT test, on vehicles with lpg
conversions is it checked when running on petrol or gas? I thought it
was tested on what the vehicle was running on at the time it is
presented for the MoT but my B-in-Law was told it has to be tested on
petrol (and failed).

On 2 Mar, 13:26, "redwood" wrote:
When the emissions are checked for the MoT test, on vehicles with lpg
conversions is it checked when running on petrol or gas? I thought it
was tested on what the vehicle was running on at the time it is
presented for the MoT but my B-in-Law was told it has to be tested on
petrol (and failed).


i had one in one in last week & how ever the vehicle is presented they
have to test it, in your b inlaws case it was presented in lpg so it
has to be tested as presented.

i should imagine they are not sure on how to test a lpg vehicle, id
take it back & point them to the testers manual.

quote

Vehicles which run on more than fuel (eg petrol and LPG) should be
tested on the fuel they are running on when presented.
There is a slight difficulty with LPG vehicles: the hydrocarbons are
propane rather than hexane. So the HC reading obtained must be divided
by the propane/hexane equivalency factor (PEF) marked on the gas
analyser. For example:
An LPG vehicle gives a HC reading of 700 ppm.
The PEF marked on the machine is 0.48.
So the actual MOT value is
700/0.48 = 1458 ie fail. /quote

In uk.rec.cars.maintenance wrote:
On 2 Mar, 13:26, "redwood" wrote:
When the emissions are checked for the MoT test, on vehicles with lpg
conversions is it checked when running on petrol or gas? I thought it
was tested on what the vehicle was running on at the time it is
presented for the MoT but my B-in-Law was told it has to be tested on
petrol (and failed).


i had one in one in last week & how ever the vehicle is presented they
have to test it, in your b inlaws case it was presented in lpg so it
has to be tested as presented.

i should imagine they are not sure on how to test a lpg vehicle, id
take it back & point them to the testers manual.

quote

Vehicles which run on more than fuel (eg petrol and LPG) should be
tested on the fuel they are running on when presented.

I wonder if a hybrid that can be locked in 'battery' mode would work for
this.

wrote in message
ups.com...
On 2 Mar, 13:26, "redwood" wrote:
When the emissions are checked for the MoT test, on vehicles with lpg
conversions is it checked when running on petrol or gas? I thought it
was tested on what the vehicle was running on at the time it is
presented for the MoT but my B-in-Law was told it has to be tested on
petrol (and failed).


i had one in one in last week & how ever the vehicle is presented they
have to test it, in your b inlaws case it was presented in lpg so it
has to be tested as presented.

i should imagine they are not sure on how to test a lpg vehicle, id
take it back & point them to the testers manual.

quote

Vehicles which run on more than fuel (eg petrol and LPG) should be
tested on the fuel they are running on when presented.


This may have changed. On my last MOT, the new computerised system was used.
The system said LPG (as this is what's on my log book), & the tester said it
had to be tested on this, & the limits were the same as for petrol, not the
non-cat limits it used to be. My old car with it's closed loop system
wouldn't have stood a chance, but this sequential system flew through.

On Wed, 07 Mar 2007 20:34:01 GMT, "Dave Griffs"
wrote:

This may have changed. On my last MOT, the new computerised system was used.
The system said LPG (as this is what's on my log book), & the tester said it
had to be tested on this, & the limits were the same as for petrol, not the
non-cat limits it used to be. My old car with it's closed loop system
wouldn't have stood a chance, but this sequential system flew through.

i think some of it depends on the testing garage.

I havent told the dvla about my gas conversion (its certificated and
insured as lpg), so it is still petrol on the v5.
I told the tester but he had forgotten and only remembered it was gas
from the exhaust smell. he just tested it as presented using the
petrol limits but with his tester switched to LPG so it read right.