Propane vs Gasoline. did research, here are the numbers

vid809

New member
Jun 28, 2011
37
0
0
I have been living here for 2 month now, after living in the US for 10 yrs. i wanted to do my own research on gas mileage on a vehicle to know what really is cheaper to ger around. we all have a general idea that gasoline gets better MPG than propane but the gallon of gasoline is twice as expensive as propane gas (LPG)

I did this tests driving my gf to work and feeling up the tank with same amount of money. Note that while driving i made sure that there was no "tapones" or stuck traffic which would change the numbers

Here are some numbers for reference:

at the time:

gasoline RD$ 220.00 per gallon (around $5.80 american)
propane RD$ 110.00 per gallon (around $2.90 american)

Now the test:

RD$ 550.00 of gasoline in tank gave me 2.5 gallons
drove around 51 miles (82 km) thats 20.4 MPG

RD$ 550.00 of propane gas in tank gave me 5 gallons
drove around 72 miles (115 km) thats 14.4 MPG

Conclusion:
It is cheaper to use propane gas since the price of gasoline is too high.
the reason why its cheaper to use LPG is because there is a price difference of 50% (gasolline doubles de price of propane)
If the price difference was 25% then it would be the same (ex. propane $165, gasoline $220 a gallon)
so as long as propane gas stays trailing gasoline by half of the cost or by a 25% less, propane is the cheaper way to go

Now the folks in the goverment and the propane distributors know this and thats why they raise both accordingly. gasoline is waay more expensive than it should be and propane gas offer you a cheaper alternative but still make over 70 pesos for each gallon pumped. they know that as long as they stay withing the 25% range, people will still buy propane gas at $110 pesos per gallon even though they could sell it for $80

notes: car used was a 1993 Acura Legend. 3.2L v6 engine with fuel injection
trail driven was in santo domingo, from charles de gaulle esq. carretera de mendoza to ave. tiradentes (3
blocks north of autopista 27 de Febrero), there is 8 miles (12.8 km)
 

AZB

Platinum
Jan 2, 2002
12,290
519
113
thanks for the test. This is useful information. I have propane for some years in my car and i have saved a bundle on long trips.
AZB
 

LTSteve

Gold
Jul 9, 2010
5,449
23
38
Hi:
Very interesting data. What is the average cost to convert a car from Gas to Propane usage? It would be interesting to see if the cost to convert is worth the payback. How long would it take to recoup the money used to make the changeover? That would be nice to know. Thanks for your info.

S
 

cobraboy

Pro-Bono Demolition Hobbyist
Jul 24, 2004
40,964
936
113
I've done asimilar study here on DR1. IMO, your sample size is too small. You should fill up both tanks and run each dry to determine the total mileage.

The cost you haven't seen yet is the head damage caused by a dry gas stripping the lubrication off the intake valves and cylinder walls (the valve problem is eliminated with the injector system but the cylinder issue remains), as well as the need to have the propane system cleaned and recalibrated every 3 months or so for optimal performance (roughly 450 pesos, plus a new vaporizer diaphragm every 9-12 months.)

Additionally, you need to amortize the cost of the installation. A venturi system will run around $800+, an injector system will run around $2500.

Additionally, there is more to propane than just cost. There is a minimum of 20% performance degradation because of the thermal potential differentiation.

All those variable need to be factored in. I have learned all of this through experience.

In my experience, unless you have the injector system installed, the cost benefit does not outweign the cost "savings" and hassle fqactor because, at the end of the day, there are none.

Additionally, when you amortize the injector system over 60,000 miles, the cost is break even at best.

When gasoline was RD$230 and propane was RD$50, the numbers make sense. No more.
 

johnny

Bronze
Feb 8, 2003
907
74
0
hausenland.com
I've done asimilar study here on DR1. IMO, your sample size is too small. You should fill up both tanks and run each dry to determine the total mileage.

The cost you haven't seen yet is the head damage caused by a dry gas stripping the lubrication off the intake valves and cylinder walls (the valve problem is eliminated with the injector system but the cylinder issue remains), as well as the need to have the propane system cleaned and recalibrated every 3 months or so for optimal performance (roughly 450 pesos, plus a new vaporizer diaphragm every 9-12 months.)

Additionally, you need to amortize the cost of the installation. A venturi system will run around $800+, an injector system will run around $2500.

Additionally, there is more to propane than just cost. There is a minimum of 20% performance degradation because of the thermal potential differentiation.

All those variable need to be factored in. I have learned all of this through experience.

In my experience, unless you have the injector system installed, the cost benefit does not outweign the cost "savings" and hassle fqactor because, at the end of the day, there are none.

Additionally, when you amortize the injector system over 60,000 miles, the cost is break even at best.

When gasoline was RD$230 and propane was RD$50, the numbers make sense. No more.

And He also have to consider at least 2 glns of gasoline to start the car for a full tank of Propane if He is using the standard system.
 
May 12, 2005
8,564
271
83
I had a car in DR that ran on both gas and propane. I found that for city driving the propane wasn't that efficient, however for long trips to places like Cabrera from Santiago, propane was the way to go. Also I noticed that there was a loss in HP with propane when climbing hills, like the road up to Jarabacoa, especially with the AC on.
 

Chip

Platinum
Jul 25, 2007
16,772
429
0
Santiago
I have a normal propane system in my Montero Sport because I just can't afford the cost of gasoline. Also, since the propane has less power I'm less likely to drive aggressively so my savings are noticeable. I also am not in a hilly area so don't notice the lack of power. I know I will need to redo the valve seals and top end of my engine but am willing to incurr the RD20k cost over 6 years. I expect to redo it next summer.

Everybody's situation is different though and I also have an older jipeta that is very popular so parts are cheap. If I had a newer model or something that parts were expensive I might opt for gasoline.
 

vid809

New member
Jun 28, 2011
37
0
0
In your testing what about performance? Propane is inferior to gas right?

yes. propane = less power than gasoline when accelerating or going up hills

just like chip said. it actually makes me drive more grandma-like and not jam on the pedal to pass somebody for no reason which also helps.

sometimes when im going to my "suegra" house i do have to switch to gasoline cuz of the hills

i have noticed on long highway trips, propane is a must, if available

and @LTSteve it can cost you anything from 4,000 to 6,000 pesos for a propane USED kit. depends if you want simple and just drive or if you want a pressure guage to know how much in tank and a filler tube so u dont have to open trunk. You would probably save that in 2 yrs if you do a lot of hw driving
 

zoomzx11

Gold
Jan 21, 2006
8,367
842
113
Propane contains less energy. When you are doing a lot of stop and go driving I have found that its not cheaper than gasoline. When you are up to speed - highway driving- its much cheaper. Around town I drive in gasoline. The car likes it better and its more responsive. I have had my propane installation for about four years and have not had any problems or significant repairs. It has more than paid for itself in that time. It was wonderful when propane was cheap but its still a good deal at todays price.
 

johnny

Bronze
Feb 8, 2003
907
74
0
hausenland.com
yes. propane = less power than gasoline when accelerating or going up hills

just like chip said. it actually makes me drive more grandma-like and not jam on the pedal to pass somebody for no reason which also helps.

sometimes when im going to my "suegra" house i do have to switch to gasoline cuz of the hills

i have noticed on long highway trips, propane is a must, if available

and @LTSteve it can cost you anything from 4,000 to 6,000 pesos for a propane USED kit. depends if you want simple and just drive or if you want a pressure guage to know how much in tank and a filler tube so u dont have to open trunk. You would probably save that in 2 yrs if you do a lot of hw driving

4,000 pesos? not even for a carro publico. unless you want to have a bomb in you car.
 

vid809

New member
Jun 28, 2011
37
0
0
i actually work at a pawn shop here and we sell the gas tank for 1000 to 2000 pesos. i know people that drive carro publico and have a small house tank, the converter with a hose going to the intake of carburator and that makes up the expensive part, the rest is hoses and crap. and a switch to flip the system. note that i said USED.
 

vid809

New member
Jun 28, 2011
37
0
0
and by the way, propane does not go around exploding like people think. it has to be in an enclosed area and have something to ignite it. so if you have propane leaking you will smell it before you blow up. and as soon as u open the trunk or close the main valve in the trunk, thats it, no risk
 

belmont

Bronze
Oct 9, 2009
1,536
10
0
and by the way, propane does not go around exploding like people think. it has to be in an enclosed area and have something to ignite it. so if you have propane leaking you will smell it before you blow up. and as soon as u open the trunk or close the main valve in the trunk, thats it, no risk
How about the tank blowing after the car trunk burns due to an overheated catalytic converter?
 

cobraboy

Pro-Bono Demolition Hobbyist
Jul 24, 2004
40,964
936
113
and by the way, propane does not go around exploding like people think. it has to be in an enclosed area and have something to ignite it. so if you have propane leaking you will smell it before you blow up. and as soon as u open the trunk or close the main valve in the trunk, thats it, no risk
Incorrect.

Propane is heavier than air. It will settle in low spots and WILL ignite if a spark or flame hits it.
 

belmont

Bronze
Oct 9, 2009
1,536
10
0
There has to be somthing dangerous with those tanks. According to BOCA building codes in the US, in my highrise apartment, I can pipe natural gas to my grill on the balcony but not permitted to use a grill with a tank.
 

vid809

New member
Jun 28, 2011
37
0
0
whaterver your argument is guys, this post is not about how safe or unsafe it is. it's about COMPARING THE GAS MILEAGE ON BOTH.
 

vid809

New member
Jun 28, 2011
37
0
0
Incorrect.

Propane is heavier than air. It will settle in low spots and WILL ignite if a spark or flame hits it.

ok so i will open a hole in the bottom of my trunk to prevent this from happening. so if it leaks it can funnel into the hole and fly away!!!!! thank you. you have saved my life. the gods of propane gas must be proud of you