Quote:
Originally Posted by shuvc Do the various numbers in the pollution control readings provide one with an understanding of the health/efficiency of the car?
I was comparing the readings for my car taken during summer 07 and winter 07, at Kolkata. On both occasions the car passed the check, but there seemed to be a lot of difference in the readings. Summer 07, Winter 07 readings for my car are given below.
Car: Baleno (Petrol)
CO - the regulation is 0.5% vol
0.004, 0.019 (% vol)
HC - the regulation is 750 ppm
1, 15 (ppm)
CO2 - no regulation specified
11.15, 4.93 (% vol)
O2 - no regulation specified
0.75, 11.63 (% vol)
Lambda - no regulation specified
1.047, 2.648
PEF - no regulation specified
0.542, 0.542
AFR - no regulation specified
15, 38
# Does this indicate that there is more carbon content/unburnt fuel in the exhaust, during the Winter 07 reading?
# Are the differences in figures acceptable?
# Why would these numbers change over a 6 month period? |
Yes, the pollution control reading tells u the health/efficiency of the car.
Its directly related but we should also consider the health of the cat also as the readings are taken downstream of the cat.
A decently tuned engine with a bad cat can give high readings also.
Need to consider your engine and your cat for this.
If engine gives mileage and power and emissions are crazy then u know its ur cat !!
An inefficient engine will not burn cleanly, u will notice loss in power and mileage.
Winter/summer will not make so much of a diff if the cooling "system" is working correctly...
I wouldn't go so far and say that summer/winter is causing this, I would consider the state of the engine at the time of taking the readings..
how well mantained/tuned was the engine at time of those readings.
I've never heard of AFR of 38
Your lambda readings say 1.047 and 2.648 , 2.648 sounds very lean.
#High CO is due to incomplete burning of air fuel mix , something which we see when engine is running rich.. e.g in the morning when the ECU is in open loop, it just adds more fuel , u end up with high CO readings.
the cat is not able to completely oxidise the gasses and u get higher readings
Now if an engine is having above average CO readings during normal operating temperture in closed loop u can guess there is something wrong with the tune/cat.
the readings for a 4 gas analyser such as the one used for your baleno takes readings while running at a high rpm ..so definately its at operating temp and not being affected by winter/summer..
High HC and CO are due to richer mixtures in engine and incomplete oxidation in the cat
O2 and CO2 increase with leaner mixtures .. because of more oxygen in the mix, this again causes more oxidation in the cat
# dont know what are the threshold values for these in India if they are good enough for clearing the pollution checks in India, is the Baleno EuroII or EuroIII compliant ?
#Within 6 months anything can happen, u may require valve clearance adjustment, o2 sensor replacement, may have damaged cat, spark plugs have become dirty, ignition timing may be out of spec,EGR valve and PCV valve maybe not working correctly etc etc its a huge list..
anything can make ur numbers fluctuate between ur 1st and 2nd set of readings
But atleast the summer/winter wont cause much deviation.