Convert 1991 560SEL to CNG? - PeachParts Mercedes-Benz Forum

MEPEH · #1 09-24-2012, 12:26 PM

I'm very interested in this too. I've had lots of cars on propane in europe and once i moved to US, everyone looks at me like a weirdo, when i mention natural gas cars.

The price of installation is pretty high here though. I could get one installed in eastern europe for about 1000 euro, and it had injectors in the intake. Would start on regular gas first, and once warmed up will switch to propane automatically. Savings were huge on gas.

Not sure why americans hate it. I have a 5.0 Engine in my CL500 and i barely touch the throttle to save gas. I'm definitely not using all 320hp of that engine. I think between 2000-3000rpm i'm only at about 200hp. Why not convert to gas and save money.
Plus in CA you get access to the Carpool lane if you have natural gas.

I'll follow this thread and watch how it goes. I've done it myself once and routing the copper lines is a *****. Everything else is pretty straight forward

Threads like these show up more and more, unfortunately, none of the ones i'm subscribed ended up with success.

Other things to remember is the engine will run colder on NatGas. And NatGas doesn't have the lubrication properties of regular gas, so you need to look into using other oils. They had special oils in europe for these applications (same price as normal oils)
Someone mentioned that there's less energy in NatGas. The Octane number is much higher, i think it's somewhere below 110 Octane.
The systems let you adjust the flow of gas so you can turn it down a bit and have equal consumption on both fuels.

I really dig the idea. Just not sure if it makes sense financially to get the installation at 5000$.

Can someone with good math skills, calculate, how much time it will take to recover the investment ?

JamesDean · #2 09-24-2012, 01:17 PM

Quote:

Originally Posted by MEPEH

I'm very interested in this too. I've had lots of cars on propane in europe and once i moved to US, everyone looks at me like a weirdo, when i mention natural gas cars.

The price of installation is pretty high here though. I could get one installed in eastern europe for about 1000 euro, and it had injectors in the intake. Would start on regular gas first, and once warmed up will switch to propane automatically. Savings were huge on gas.

Not sure why americans hate it. I have a 5.0 Engine in my CL500 and i barely touch the throttle to save gas. I'm definitely not using all 320hp of that engine. I think between 2000-3000rpm i'm only at about 200hp. Why not convert to gas and save money.
Plus in CA you get access to the Carpool lane if you have natural gas.

I'll follow this thread and watch how it goes. I've done it myself once and routing the copper lines is a *****. Everything else is pretty straight forward

Threads like these show up more and more, unfortunately, none of the ones i'm subscribed ended up with success.

Other things to remember is the engine will run colder on NatGas. And NatGas doesn't have the lubrication properties of regular gas, so you need to look into using other oils. They had special oils in europe for these applications (same price as normal oils)
Someone mentioned that there's less energy in NatGas. The Octane number is much higher, i think it's somewhere below 110 Octane.
The systems let you adjust the flow of gas so you can turn it down a bit and have equal consumption on both fuels.

I really dig the idea. Just not sure if it makes sense financially to get the installation at 5000$.

Can someone with good math skills, calculate, how much time it will take to recover the investment ?

Subscribed. Interesting stuff. Recovery time would be based on driving I would imagine. I drive a lot each week so I think I could recoup the 5k investment in 2-3 years. Assuming the car would achieve an equivalent 35 mpg or so. (I used my original calculations for buying my 300D @ 35 mpg).

MEPEH · #3 09-24-2012, 01:35 PM

To make it easier to calculate.. this is what i need to know ( to convince my wife)

Filling up the tank 26 gallons @ 4.4$ is about 120$
And it will go about 350 miles

How much would i have to pay for NatGas to go 350 miles ?

one more thing i remember.. the smell of gas from cheap installations

God it smells like gas in the garage, interior of the car, under the hood. Equivalent of a poorly maintained diesel engine, but add the smell

JamesDean · #4 09-24-2012, 03:58 PM

Quote:

Originally Posted by MEPEH

To make it easier to calculate.. this is what i need to know ( to convince my wife)

Filling up the tank 26 gallons @ 4.4$ is about 120$
And it will go about 350 miles

How much would i have to pay for NatGas to go 350 miles ?

one more thing i remember.. the smell of gas from cheap installations

God it smells like gas in the garage, interior of the car, under the hood. Equivalent of a poorly maintained diesel engine, but add the smell

Well you're getting about 13.5 MPG with that information. As best I've seen so far CNG will often get 2-4 MPG below the gas number. (I looked on fueleconomy.gov and went year by year under car type and looked at bi-fuel).

The nearest station to me was at $2.10/gallon.

So going with 9-11 mpg at $2.10/gallon you will go, 230 miles to 286 miles. Cost will be about $55 to fill 26 "gallons".

To do 350 miles, $66.81 to $81.60.

So your savings would be, ~$50/tank. So for this to pay itself off (at $5k investment)you'd have to do 100 tanks worth or 35,000 miles. Given the average per year is like 15-17k...about 2-3 years.