Benefits of Propane

[djagusch]

Originally Posted by Terry Metro Lawn

Actually propane has about 7% fewer BTUs than gasoline but runs a more robust 104 Octane. Typically usage is close especially given shrinkage.

Fuel pricing differs per region because of transportation costs. It's up to the Districts as far as pricing is concerned. I believe a savings of 15-20% is built in to the calculator. Many do much better than this. After hitting "enter" you can input your current local pricing to get a better idea of savings.

A full 33# alumninum cylinder weighs about 55# and carries roughly 7 gallons. Propane weighs about 4.24# vs gasoline at about 6. Brackets are around 5-7. It depends on the mower whether or not two tanks would be mounted. Sometimes we get a day out of one 43# tank. We try to match the OEM operating time.

MN? You may already be doing business with us. ;-)

I was using 91600 btu's per gallon of propane. Unleaded gasoline has 114100 btu's per gallon. Which is 20% difference.

Octane to my knowledge isn't more robust but lets the fuel burn slower. You can take advantage of the slower burn with a higher compression ratio. If you don't raise the compression ratio the higher octane rating doesn't do much of anything.

Are you increasing orifice size by 7%? If so that flows way more than 7% of fuel.

Not a customer yet. I have a automotive engineering technolgy 4yr degree from Mankato State (MN college). Worked with E85 in cars in the mid 90's, competed in the clean snowmobile comp with direct injection (2stroke), and raced motorcycles with E30.

Ever time I talk to my U of M ME graduate who works for a company doing clean diesel technolgy about running propane on the mowers says it's not the most economical with conversion costs and price points yet. He does say it's a clean burn and the engine valves have less build up.

I'm guessing if a mowing company has a full time mechanic with 5 crews or more you could get over the intial hump of set up costs as he could learn to buy individual pieces for kits instead of the $3K cost with training. Manage your mower purchases so you can transfer kits to the new mower would also help.

[djagusch]

Originally Posted by Terry Metro Lawn

BTW C2W, if you want to check out individual studies have a look here:

http://www.autogasusa.org/propane-ve.../case-studies/

Although my company is sited here (nothing succeeds like success, right?) this was independently done.

Is there any true numbers of the case studies? All I read was estimates, would like to see actually numbers.

[Terry Metro Lawn]

Originally Posted by djagusch

Is there any true numbers of the case studies? All I read was estimates, would like to see actually numbers.

I'll research this and post what I find.

Stay tuned...

[Terry Metro Lawn]

In the mean time, there are some references here:

http://www.allpropanemowers.com/v.php?pg=237

[djagusch]

Terry,

This is the question "How do you get better gal/hr if a gal has less btu's?".

I read the article posted it states 30% less fuel, does he mean that or 30% less money? At comparing what fuel prices? Gas right now is $3.30/gal propane is $1.99/gal. Is it 30% of that or $4.50/gal gas?

I run kawi fd750d carbed engine and gets 1.3gal/hr. A kawi fd791d dfi (fuel injected) gets 1gal/hr. Both are the same engine but different methods of fuel delievery. What would a propane model get for fuel usuage? Onyx has a kit for the fd750d, I'm running scag turf tigers with 61" decks. Based on btu's on the dfi gal/hr you would be at 1.2gal/hr on the carbed it would be 1.56gal/hr. If you are getting the carb spec I'm almost better off buying the dfi (only losing .30/hr) with the more common set up.

Gal/hr is a unit of measure that all lco's would understand to compare it to. Also most lco's are getting oil changes at 100hrs so their is little savings there compared to the article.
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[Terry Metro Lawn]

Originally Posted by djagusch

Terry,

This is the question "How do you get better gal/hr if a gal has less btu's?".

I read the article posted it states 30% less fuel, does he mean that or 30% less money? At comparing what fuel prices? Gas right now is $3.30/gal propane is $1.99/gal. Is it 30% of that or $4.50/gal gas?

I run kawi fd750d carbed engine and gets 1.3gal/hr. A kawi fd791d dfi (fuel injected) gets 1gal/hr. Both are the same engine but different methods of fuel delievery. What would a propane model get for fuel usuage? Onyx has a kit for the fd750d, I'm running scag turf tigers with 61" decks. Based on btu's on the dfi gal/hr you would be at 1.2gal/hr on the carbed it would be 1.56gal/hr. If you are getting the carb spec I'm almost better off buying the dfi (only losing .30/hr) with the more common set up.

Gal/hr is a unit of measure that all lco's would understand to compare it to. Also most lco's are getting oil changes at 100hrs so their is little savings there compared to the article.
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Whenever I hear of a customer useing LESS fuel I have to smile. Many times this is due to "shrinkage". There's no other explanation. Your math is sound.

I can't vouch for everybody's pricing but you should be able to do better than what you state. It depends on your load.

Many times we will provide a dispenser if the cost is justified and the ROI flies.

We're a propane company.

When he mentions 30% less I believe he is talking about cost not gallons. I hear this number quite a bit.

[Terry Metro Lawn]

Texas offers substantial rebates through PERC. Here are some testamonials:

http://www.youtube.com/watch?v=MPstGv9v9Ps