Team-BHP - CNG vs LPG Comparision

Quote:

Originally Posted by SAS (Post 1842013)

Essentially an open loop system is manually adjusted (2 adjustments are available, 1 each for mid-rpm and idle). It's more like a carburetor. You're right, in a closed loop, the AFR is adjusted by the sensor, the lambda control unit. The closed loop system is far better, especially for emissions and mileage, but it's difficult to diagnose when something goes wrong, hence I decided to give it the skip. I can always go for it later on. Entry level LCS systems start from Rs. 2000.

Is your car fuel injected or carbureted?. A timing advance of around 4 deg is found to work well when running on Gaseous fuel so to account for the slow burning characterstics of the fuel.

How much the Ignition Advance retard circuit is going to help in Electronic cars i an doubtfull as the timing is controlled by the ECU / computer. However for the Carbureted cars this circuit is really a boom.

What is LCS? If you go for an electric throttle butterfly in between the vaporizer and engine gas inlet pipe the responce will be much better.

As for the Engine oil here is the 20W50 Oil for LPG / CNG engines by castrol

Castrol India - CASTROL GTX CNG

Quote:

Originally Posted by manishalive (Post 1842159)

What is LCS? If you go for an electric throttle butterfly in between the vaporizer and engine gas inlet pipe the responce will be much better.

As for the Engine oil here is the 20W50 Oil for LPG / CNG engines by castrol

Castrol India - CASTROL GTX CNG

Thanks Manish. Let me try the 4 degrees thingy. I'm not sure how much mine has been adjusted

I did see the castrol CNG fuel. It's something generic for cabs / autos, etc. I'd prefer going with magnatec or gtx. Also saw mobil1 5w50; not sure where it is available and it's price - it looks like an overkill. I'm more inclined on GTX 20w50, since anyway I shall be changing ever 10k kms.

Quote:

Originally Posted by ajitkumarlb (Post 1743918)

I had a ZEN 12 year old, had gas kit fitted and RTO endorsed on my RC book so should not be an issue

Now to my question: the ZEN gas job was done by a local mechanic, though no major problems with the kit - after sale service was a night mare.

So want to go with some professional for my Santro AT conversion now. I have been researching net & this fourm. and have narrowed down to two retro fitter EcoGas in Jayamahal Extension and Dars Auto on Queens road. (Bangalore)

any reviews of these place?
OR
any one recomend any one fitter in North Bangalore?

Ajit, EcoGas in Jayamahal Extension is no different from any other retro fittment centre. I had got them plug a leaking coolant hose. I should appreciate the material quality he used.
If you are really bent upon getting ur car converted you can go to this centre.

Quote:

Originally Posted by nitrous (Post 952220)

Isn't it the toroidal tank thats easily available?

From the picture it looks like this is fitted whether the spare tyre is located. If that's the case, then where does one keep the spare tyre?

Quote:

Originally Posted by rjvora_2000 (Post 958117)

Rto visit is must after CNG or LPG.
There is one endorsement in RC book as well.
Corrolla can have CNG installed.
There are lot of brand in the market which can be installed.
Money you spend will change 10% to 15% deppending up on the brand you chose.

Can RTO endorsement be done from any RTO or does it have to be the one whether the car was originally registered i.e. for a Pune registered car, can one get the CNG conversion done in Bombay & also RTO endorsed in Bombay? Are there dealers in Bombay who will get this done?

Quote:

Originally Posted by hrman (Post 725278)

Found this link on the net. Its about a cost comparison b/w Petrol/ CNG/LPG. Hope you find it useful.

Select the alternate fuel that best suits your requirement. Select between CNG or LPG

That link isn't working now. However, this link on the same site works.
Converion Cost Calculator

Quote:

Originally Posted by phamilyman (Post 725449)

Hrman, while the website gents are in their wisdom pushing LPG, I can tell you that the maintenance amounts written are completely WRONG. So is the drop in power! Misleading website is all i can say.

Looking at their calculator, it seems as if LPG just gives a 12% cost reduction, which doesn't seem much when running 45 odd kms a day. i.e.
your fuel costs reduce from Rs 200 a day to Rs. 176 This isn't really a significant reduction. So CNG seems much better, or am I missing something?

Also, what kind of maintenance issues are there with CNG - i.e. is it just more frequent spark plug changes or something more - 4 sparks cost 200Rs, so that's not much.

I have Swift Petrol - and I am only most going to be driving in the city and if your driving is mostly to get from Point A to Point B & not for pleasure, is the power reduction significant?

Quote:

Originally Posted by SAS (Post 1842349)

What is the difference between a CAB and your car?? As CNG Engines run hotter there is a tendency for the engine oil loose is property. More over to withstand the various levels of oil degradation caused by the gas fuel combustion process a specific Gas Engine Oil is used.

An oil sampling / analysis is done regularly to monitor TAN, TBN, Nitration, Viscosity Oxidation and Wear metal.

Quote:

Originally Posted by manishalive (Post 1850862)

What is the difference between a CAB and your car??

Regular GTX is of a Higher API grade than the CNG one. Also I've to run my car occasionally on Petrol. It makes more sense to either go for GTX or Magnatec. I've spoken to several dealers and they themselves do not recommend going for the CNG specific one. They say it's just re-branding on Castrol's part. Not sure if it's true, but GTX seems sufficient for now

Recently i went to MUL showroom to see SX4 CNG, when i opened the boot, it was having a huge CNG clyinder and there was hardly any boot space left, only 1 or 2 laptop bags could fit in.

Does anybody know, whether CNG clyinders come in toroidal shape ( Fitting in the spare tire space)?? LPG Clyinders do come in toroidal shape, but Honda showroom salesman told me that within a few months toroidal CNG clyinders are going to be lauched. Does anyone have any news/knowledge on this front

Also MUL salesman told me that Maurti has discontinued its LPG line off cars because it adversly affects the engine (As per him the engine life is reduced by as much as 50%) IS THIS TRUE??

Quote:

Originally Posted by sunnyside (Post 2104616)

Regarding the SX4 space, I felt that it should have more space than just for 2 laptop bags. Maruti is using a 65 litre tank only.. You do face a space constraint with a CNG tank with is a downside tradeoff, however the SX4 has a pretty large boot.

CNG cylinders do not currently come in toroidal shape IMHO. The pressure is pretty high, they are constantly filled with ~200bar at the pumps (that's almost 100 times more than the pressure you fill in your tyres)

Regarding engine premature wear, I've been using CNG since the past 8 months and haven't had any single issue with the engine. Yes the engine does run hotter, so you may switch to a slightly thicker engine oil (I changed from 20w40 to 20w50) or go in for semi synthetic or fully synthetic. Maruti has modified the valve seats which get pretty hot when running gas, plus they improved the suspension. I must say, Maruti has really come out with a well thought product. After fitting a CNG tank in the rear, the rear suspension does take a hit and also wears more quickly.

Apart from suspension, there are no adverse impacts on the car, especially the engine. Another benefit of CNG or LPG is that they do not dilute / contaminate the engine oil, thus increasing the life of the oil and providing better protection to the engine.

Quote:

Originally Posted by sunnyside (Post 2104616)

Did you manage a test drive ??
Was a test drive even available for the SX4 CNG ?

Quote:

Originally Posted by SAS (Post 2107694)

Regarding engine premature wear, I've been using CNG since the past 8 months and haven't had any single issue with the engine. Yes the engine does run hotter, so you may switch to a slightly thicker engine oil (I changed from 20w40 to 20w50) or go in for semi synthetic or fully synthetic. Maruti has modified the valve seats which get pretty hot when running gas, plus they improved the suspension. I must say, Maruti has really come out with a well thought product. After fitting a CNG tank in the rear, the rear suspension does take a hit and also wears more quickly.
Apart from suspension, there are no adverse impacts on the car, especially the engine. Another benefit of CNG or LPG is that they do not dilute / contaminate the engine oil, thus increasing the life of the oil and providing better protection to the engine
.

All engine running of GAS will have premature engine wear, valve recession is much more compaired to a petrol one. However as said if the seats are of harder material and are different than petrol then the effect is minimised. you might also need to have a different geometry valve.

For Gas engine there is special formulated engine oil from Castrol which is specially formulated to run in hotter engines.

Also a normal side effect of cars running on gas is @ approx 40 k kM running, the the rings give away and you have go for a ring job.