Cng Conversion - Have You Done It?

[BigKev]

Hello All,

In doing some searches I have found a couple of members that have done a LPG conversion(notably Monty) and are quite happy with the results. A few (EVO and tjlr(sp?) I think) thought of doing the CNG conversion but no one here seems to have done it. It also seems to be the way the Thai government want the Alternative fuel program to go instead of LPG, this of course makes me suspicious - Thanskin now owns CNG distribution I would assume.

So have you converted? What did you convert? Is it worth it? Why is it the Thai governments choice fuel?

I also found an annoucement online that starting next year Chevrolet will begin selling a CNG/petrol Optra and soon after that a CNG/diesel colorado.

Cheers,

BigKev

[kasi]

Nearly every taxi and samlor on bkk runs on cng.

Else where in the country distribution in still spotty.

Advantages are that the fuel is cheap and burns very clean. (engines last longer and require less maintenance)

Disadvantages are reduced range out of a tank of fuel.(you can still run gasoline out of your gasoline tank when you run out)

The cng tank takes up significant space in the trunk of a car like a corolla.

It's a good idea but there are definite inconveniences. Unless you drive a lot the savings wont be significant.

[soap]

hello big kev

i have just had my car changed over to lpg and after 2 weeks i am very pleased so far that i changed over.

my fuel bills have been cut by at least 50% i have not noticed any power loss.

i look at it this way,i am sure within one year i will have saved on my fuel bills to pay for the conversion 20,000 baht.

i was going to try and sell my car a daewoo espero 2 litre auto, knowing that the thais dont like to buy the daewoo cars.

but i have had this car for over 8 years now and i love the car except for the fuel consumption ,so now i will keep the car for a few more years without having monthly payments to fork out on a new vehicle,

and when the time comes to sell the car if i point out what my fuel bills are after the conversion hopefully it will prove a good selling point

[monty]

Major reason for Thailand trying to promote CNG is because they have it themselves from their offshore gasfields.

LPG is still a (by)product distilled from oil, which Thailand has to import and pay for with US$...

Kasi, the majority of the taxis and all the samlor are running on LPG, not on CNG! A CNG tank I believe weighs some 80 Kg compared with the 25 something kg for a LPG tank...

LPG stations are already spotty outside the bigger provincial cities, CNG is pretty non existent there...

So I myself also have never spoken with somebody done a CNG conversion, I guess at the moment it's only viable for people living in Bangkok and hardle never venture out of the big city!

Do note that autonomy is only some 280 km's on a CNG tank (or even less on a big gas guzzling car) compared to around 400 km on the standard 58 liter LPG tank...

I'm still happy as ever with my LPG conversion

[COBBER]

CNG is better suited in countries that have a gas grids for houses, where you can refill at your own house. With CNG it takes at least 20 minutes to fill your tank wheras with LPG it just takes a bit longer than refilling with petrol. IMO LPG is the better option for Thailand.

[Moonfruit]

I will be taking the LPG plunge next week (payday tomorrow ya know!) and am looking forward to hours in the yard trying to build something around the tank to conceal it in the boot.

Also looking forward to reduced fuel costs!

[BigKev]

Thanks for the information and opinions!! Glad to know about the 20 minutes to fill up with CNG and also the lack of range. Those are both some major issues!! LPG is looking like a much better alternative.

Some follow up questions for you guys - What is the cost of CNG vs. LPG not just the conversion but also the gas itself and are they equally efficent? I know basic LPG conversion is 18-20000 baht for 1st generation conversion kits but are the more advanced LPG conversion available in Thailand - those that lessen power loss and increase efficiency and what do they cost? Does conversion to LPG also help extend engine life and lessen maintenance? Is LPG adaptable to a diesel engine like CNG? It seems to me that the only real savings now in Thailand with CNG vs. LPG is PTT is keeping CNG low - is it artifically low or low because the Thais have reserves? Monty, I will be settling near Pattaya, where are the LPG stations there? Also has anyone converted a Ford Escape or Mazda Tribute?

Sorry for more questions guys, but when I know more it makes me want to ask more. Thanks for all the help.

Cheers,

BigKev

[teej]

Thanks for the information and opinions!! Glad to know about the 20 minutes to fill up with CNG and also the lack of range. Those are both some major issues!! LPG is looking like a much better alternative.

Some follow up questions for you guys - What is the cost of CNG vs. LPG not just the conversion but also the gas itself and are they equally efficent? I know basic LPG conversion is 18-20000 baht for 1st generation conversion kits but are the more advanced LPG conversion available in Thailand - those that lessen power loss and increase efficiency and what do they cost? Does conversion to LPG also help extend engine life and lessen maintenance? Is LPG adaptable to a diesel engine like CNG? It seems to me that the only real savings now in Thailand with CNG vs. LPG is PTT is keeping CNG low - is it artifically low or low because the Thais have reserves? Monty, I will be settling near Pattaya, where are the LPG stations there? Also has anyone converted a Ford Escape or Mazda Tribute?

Sorry for more questions guys, but when I know more it makes me want to ask more. Thanks for all the help.

Cheers,

BigKev

I'm not sure about the 20min fill time for CNG, is that really true? I thought there was a "fast fill" of CNG where the gas is not as compressed as in an overnight fill -- is this 20mins the "fast" version? I've seen the queues at the PTT on Vipawadee near Central Ladprao, and after hearing the 20min fill time, wondered if that was really true... that's a long long time...

Re CNG BigKev, I was considering it on an old Range Rover of mine a few months back. Someone posted about the tank weight and sizes and, while mostly correct, after I called around and did some minor research, there were CNG tanks around that were made of lighter weight materials and were not as heavy as the early tanks were... however, the nature of CNG (it's properties as a gas) remains to be a limiting factor re: the size of the actual tank itself. Weight, however, can be reduced significantly (and at a significant price) by using different tank materials.

Re: prices of conversion -- I've heard that LPG conversions can be as low as 10k baht, but I'm sure that's pretty much the lowest-end stove-top burner conversion with shoddy product and shoddy technicians on the install. CNG conversions can run up to 100K baht for the best installs, so there is a clear price difference. On average, I'd say CNG conversion is around 2x the price of it's LPG conversion, either at the high end or low end.

At the time I researched it, I believe CNG was selling at about 1baht/Litre less than LPG, so around 10-15% cheaper (I believe LPG prices are around 9baht/litre?)... The breakeven point for CNG would be a bit further down the line if compared to LPG...

I've heard that the car suffers less power loss at the hands of CNG, but I'm sure this is debateable. Re: diesel engines, I believe that under either situation, diesel engines still require some about of diesel in the mixture to burn, so you are not totally "turning off" the fuel line when using CNG/LPG... i.e. you still must use some amount of diesel.

If you live near Pattaya, I'd assume that LPG stations are more common in those areas, so I'd probably recommend LPG. Also, it's true about the CNG tanks not being able to run for the distances that the LPG tanks can run, so that is something else to consider if you don't live in BKK.

Finally, I decided against the conversion, just because I didn't want to mess with my Range Rover. Range Rover does not recommend the conversion, BMW and Saab strongly strongly recommend against any conversion, so I figured I'd just pay at the pump. However, Volvo and Benz seem to have a lot of conversions running around bangkok and they seem to be doing well enough. Re: your Escape or Tribute, I'm not sure if it is suitable, I would recommend contacting the companies themselves for their opinions and suggestions. (of course they will probably not recommend it, but you get the point... if you don't see Escapes and Tributes converting, there must be some sort of issue... that was my position on BMW and Saab, as I know 0 people with either car that has converted (besides maybe the oddball who has dropped a japanese engine into their Bimmer).

Good luck on your research and I hope you can save a couple of baht at the pump!

[monty]

There's two stations (LPG) that I use.

The first is on Sukhumvit, when driving towards North Pattaya coming from Naklua, you'll see on your lefthand side a Jet fuel station. Just behind it is another fuelstation with a green sign in Thai language only. This is the station selling the gas, just follow the Taxi meters All this is about 300 meters before you reach Mini Siam, with the drive through MacDonald restaurant...

The second is also on Sukhumvit road, driving to North Pattaya coming from central Pattaya, about 1 km before you reach the North Pty traffic lights. It's a little older looking PTT station. LPG pumps are seperat in the back of the compound...

Supposedly there is 1 CNG station, on Sukhumvit somewhere between Jomtien and Sattahip...

[BigKev]

Monty,

What is the price of LPG at the stations in Pattaya?

Cheers,

BigKev

[maverick7]

Hi

I own a avanza. Would like to switch to CNG. Any recommendation for good installer around Hadyai?

Installation cost for sequential and mixer.

Those have converted their avanzas. Could you share your experience on CNG

Thanks in advance.

Regards;

Maverick

[Gary A]

Years ago Honda had a cng car in the US. The fuel came from the natural gas supply in your house. The car came with a small pump and the idea was that when you got home, you would plug in the filler hose, turn on the pump and by morning your car tank would be filled. It was a resounding failure. Gasoline was still cheap and people just didn't want the bother. I think that today the feeling may be different.

[aussiebebe]

I saw this thread was started in 2006 - what's the latest (2010) news about NGV conversions? If anyone's recently converted their car to run on NGV, I'd be interested to hear opinions. In particular, what's the current price for a decent conversion? does the conversion include upgraded engine components to cope with the gas? does the manufacturer warranty become voided? does it affect insurance premiums?

Other board members have claimed NGV causes serious damage and requires an engine re-build. has anyone any experience of this? what went wrong and why? I'm bemused that the Thai government is currently pushing taxis to run on NGV:

http://www.bangkokpost.com/business/econom...r-taxis-pitched

The government is targeting the taxi sector first as it consumes the largest volume of LPG. The government switched half of Bangkok's 60,000 taxis from LPG two years ago. Mr Norkhun said converting the rest to NGV (natural gas for vehicles) would cost the government 1.2 billion baht. "We want to push the demand for clean natural gas instead of importing LPG. We still have our own natural gas reserves," he said.

[tvmax]

Chevy Optera can come from the factory with CNG and it has full warrenty. It does not take 20 min to fill. It takes maybe 2 Minutes. There are stations almost everywhere now and it is cheaper than LPG. As oil prices rise NGV does not as it is not a byproduct. It is a reduced distance covered compared to the LPG tank of the same dimension. I love my NGV.

[katabeachbum]

Chevy Optera can come from the factory with CNG and it has full warrenty. It does not take 20 min to fill. It takes maybe 2 Minutes. There are stations almost everywhere now and it is cheaper than LPG. As oil prices rise NGV does not as it is not a byproduct. It is a reduced distance covered compared to the LPG tank of the same dimension. I love my NGV.

I have not seen one CNG station south of Prechuap/Chumporn. Range for most factory fitted cars is 200km on CNG.

[stevehaigh]

Chevy Optera can come from the factory with CNG and it has full warrenty. It does not take 20 min to fill. It takes maybe 2 Minutes. There are stations almost everywhere now and it is cheaper than LPG. As oil prices rise NGV does not as it is not a byproduct. It is a reduced distance covered compared to the LPG tank of the same dimension. I love my NGV.

hi, i noticed a chevy optera at the NGV pump the other day and asked the lady driver about it. she said it was a nice car and yes, only about 2 mins to fill. but is that correct that the range is only 200km? does it have a petrol backup like lpg conversions do? if not, 200km isn't that far with no backup, you must be on constant lookout for NGV filling?

i realize i should go into a dealer and look but not convenient right now. how much is a new one and have you worked out the actual cost per km?

thx steve

lazy me, i just found the website http://www.chevroletthailand.com/en/pricing_1.php

they are at about 719,000 for CNG manual, toyota altis starts about about 750,000 for same thing.

Edited July 16, 2010 by stevehaigh

[monty]

One of my taxi drivers has one of those factory built CNG Chevrolet's.

He confirms very cheap to run, but 200 km range (highways) is a bit of a PITA...

And virtually no trunk room left, the tank is massive.

It does have a petrol tank as well, you'd be stranded somewhere pretty quick otherwise!

[katabeachbum]

One of my taxi drivers has one of those factory built CNG Chevrolet's.

He confirms very cheap to run, but 200 km range (highways) is a bit of a PITA...

And virtually no trunk room left, the tank is massive.

It does have a petrol tank as well, you'd be stranded somewhere pretty quick otherwise!

NGV needs more than double amount CNG than LPG, so tank must be double or range is half. To total confusion CNG is sold in kg, not litres, and as I recall there are 4 litres CNG in one kg, compared to LPG two litres in one kg. Petrol approx 1,15 litres in one kg.

Same thing happens when running E85, 85% ethanol blended with petrol. range half.

Edited July 17, 2010 by katabeachbum

[schlomo]

i bought the corolla altis auto gear with factory fitted CNG system last december.

had a honda crv before.

i love the car - even though the range is around 200kms.

CNG stations can be found everywhere around BKK.

drove down from bkk to Koh Samui in April - costs werde 430 THB (one way). filling takes just 2mins

the car saves me a lot as i drive around 30.000 kms per year.

Costs per 100kms:

CRV: approx 320 THB ( 10-11l of petrol )

Altis CNG: approx 65 THB (7.5kgs of NGV)

Direct annual savings: more than 70k THB (~6300 THB per month)

Edited July 17, 2010 by schlomo

[monty]

NGV needs more than double amount CNG than LPG, so tank must be double or range is half.

Not sure where you got that comparison!

The difference between LPG and CNG, is that LPG when compressed turns into a liquid. CNG does not compress into a liquid!

1 liter of liquid LPG will give around 250 liters of gas! When you fill up LPG it is in liquid form, hence the indicating in liters! So a 40 liter LPG tank will give you around 10,000 liters of LPG in gas form!

As CNG does not compress into a liquid, 1 liter of CNG will be just that, 1 liter of gas. Which is why to get any useful range out of a CNG tank, they have to cram in as much liters of gas as they can, and the only way to do that is by putting it in the tank at tremendous high pressure (up to 250 kg/sq cm or 3600 PSI) as compared to the 8 kg/sq cm (120 PSI) for LPG...

That's the only reason for the limited range you can get with CNG, having to carry the CNG in it's bulky gas form...

[katabeachbum]

NGV needs more than double amount CNG than LPG, so tank must be double or range is half.

Not sure where you got that comparison!

One kg of CNG in a Altis 1,6 covers approx 10 km. One kg LPG in a Altis 1,6 covers approx 20 kg. Simplest comparison there is, same car different fuels.

Petrol in same car, 1 litres covers approx 12 km.

Same driving conditions, different fuel.

[monty]

NGV needs more than double amount CNG than LPG, so tank must be double or range is half.

Not sure where you got that comparison!

One kg of CNG in a Altis 1,6 covers approx 10 km. One kg LPG in a Altis 1,6 covers approx 20 kg. Simplest comparison there is, same car different fuels.

Petrol in same car, 1 litres covers approx 12 km.

Same driving conditions, different fuel.

Very correct.

However you forget one thing, and that is that in the CNG tank, you can cram in about 15 kg of CNG.

The standard LPG tank, which is much smaller and lighter then the CNG tank, stores around 23 KG LPG (46 liters).

So getting a CNG tank which stores double of an LPG tank is simply not possible.

[soundman]

As CNG does not compress into a liquid, 1 liter of CNG will be just that, 1 liter of gas. Which is why to get any useful range out of a CNG tank, they have to cram in as much liters of gas as they can, and the only way to do that is by putting it in the tank at tremendous high pressure (up to 250 kg/sq cm or 3600 PSI) as compared to the 8 kg/sq cm (120 PSI) for LPG...

Which, IMHO, basically means you are sitting on a bomb. If the bottle ever ruptures at 3000+ PSI loading - instant death for anyone in close proximity.

Can you imagine what would happen if one of those bottles ruptured inside a passenger van? Sausage.

[katabeachbum]

One kg of CNG in a Altis 1,6 covers approx 10 km. One kg LPG in a Altis 1,6 covers approx 20 kg. Simplest comparison there is, same car different fuels.

Petrol in same car, 1 litres covers approx 12 km.

Same driving conditions, different fuel.

Very correct.

However you forget one thing, and that is that in the CNG tank, you can cram in about 15 kg of CNG.

The standard LPG tank, which is much smaller and lighter then the CNG tank, stores around 23 KG LPG (46 liters).

So getting a CNG tank which stores double of an LPG tank is simply not possible.

Having done more than 100 LPG vehicles, the standard size tanks are brutto 40, 60, 80, 120, 180 L. In addition there are dual/triple tanks, and sparewheeltanks (donuts).

So to fill up 46 liters LPG, you need a 60 liter brutto tank, if you want to be within the 80% legal limit, but tank often trimmed to accept 85%.

I dont have much experience with CNG, but to get the range of 46 liters LPG, CNG tank should be approx 240 liter brutto., which doesnt fit in cars. 100 liters CNG tank fits in car taking half the trunk of Chevy/Daewo Optra Estate, with 17-20 kg CNG capacity providing approx 200 km range. More range/tank/fuel is possible, but no trunk left

Most sold CNG tanks in LOS is def the ones used on trucks, approx 200cm long and 40 cm diameter, and they hold a bit more than 15 kg/60 liters, I d say 4 times more = 60 kg/240 litres. Most trucks have 4 to 8 of them to achieve sufficient range between available CNG fill ups.

Conclusion

Much larger tank and double amount of CNG to achive same range as LPG

Talking about CNG safety, there is now a campaign to convert fishing boats from diesel to CNG. Thats a floating bomb

[monty]

As CNG does not compress into a liquid, 1 liter of CNG will be just that, 1 liter of gas. Which is why to get any useful range out of a CNG tank, they have to cram in as much liters of gas as they can, and the only way to do that is by putting it in the tank at tremendous high pressure (up to 250 kg/sq cm or 3600 PSI) as compared to the 8 kg/sq cm (120 PSI) for LPG...

Which, IMHO, basically means you are sitting on a bomb. If the bottle ever ruptures at 3000+ PSI loading - instant death for anyone in close proximity.

Can you imagine what would happen if one of those bottles ruptured inside a passenger van? Sausage.

No necessarily a problem, there are lot's of tanks being used at that pressure or even higher! Simple scuba tanks are filled up to over 4000 PSI! They don't usually rupture!

It's simply a thing of proper quality control which admittedly might be a tad of a problem in Thailand

Or some dumb dozo trying to use an LPG tank and trying to fill it with CNG at 3600 PSI!

And although LPG might be stored at a much lower pressure, putting obviously much less strain on the tank, a rupturing LPG tank also results in a rather spectacular event, caused by the pressurized liquid state gas suddenly expanding 250 fold at atmospheric pressure!

[katabeachbum]

As CNG does not compress into a liquid, 1 liter of CNG will be just that, 1 liter of gas. Which is why to get any useful range out of a CNG tank, they have to cram in as much liters of gas as they can, and the only way to do that is by putting it in the tank at tremendous high pressure (up to 250 kg/sq cm or 3600 PSI) as compared to the 8 kg/sq cm (120 PSI) for LPG...

Which, IMHO, basically means you are sitting on a bomb. If the bottle ever ruptures at 3000+ PSI loading - instant death for anyone in close proximity.

Can you imagine what would happen if one of those bottles ruptured inside a passenger van? Sausage.

No necessarily a problem, there are lot's of tanks being used at that pressure or even higher! Simple scuba tanks are filled up to over 4000 PSI! They don't usually rupture!

It's simply a thing of proper quality control which admittedly might be a tad of a problem in Thailand

Or some dumb dozo trying to use an LPG tank and trying to fill it with CNG at 3600 PSI!

And although LPG might be stored at a much lower pressure, putting obviously much less strain on the tank, a rupturing LPG tank also results in a rather spectacular event, caused by the pressurized liquid state gas suddenly expanding 250 fold at atmospheric pressure!

Never seen ruptured tank. Cause of accidents seems to always be valves, hoses, tubes, venturies, leaks. Sloppy installation and sloppy maintance.

Shooting at a tank, steel, aluminum or composite with 9 mm does not make it blow up. You must hit the valve.

Edited July 18, 2010 by katabeachbum

[monty]

Oh, and for those interested what happens if LPG tanks get shot

http://videos.howstuffworks.com/discovery/33060-mythbusters-exploding-propane-tank-video.htm

Kind of, LPG is actually a mixture of propane and butane, but assume it has the same reluctancy to catch fire...

[katabeachbum]

Oh, and for those interested what happens if LPG tanks get shot

http://videos.howstu...-tank-video.htm

Kind of, LPG is actually a mixture of propane and butane, but assume it has the same reluctancy to catch fire...

Propane and Butane is both LPG(Liquid Petroleum Gas). Some countries use only one of them, some mix them, some use different for summer and winter. But I dont recall the difference, except Butane works better when colder than minus 30C.

[katabeachbum]

Toyota has finally blessed LOS with the ZR-FE 1,6 and 1,8 and 2,0 petrolengines used in the US and EU markets in Altis Corolla. Lower fuelconsumption, more power.

Except for the 1,6 CNG, which only remains 100k km warranty with the CNG moded ZZ-FE.

1,6 ZR-FE produces 122hp/154Nm while the old CNG moded 1,6 ZZ-FE produces a modest 109hp/145Nm running petrol