gas mileage comparison

[bamabikeguy]

Update: on flatter land than I live in, a customer weighing around 230, with the RS 35, using the GEBE 14 gear (NOT recommended, due to the heavy dutiness of the clutch), reported a GPS certified 200 mpg. If he used the 13, like GEBE recs, I'd guess he'd hit 190.

He says he's tooling around town at 1/2 to 1/3 throttle....he lurks on MB.com, one day he'll check in and brag for himself !!

 

[Irish John]

Just finished first gallon of gas on a Honda GX50 and came to almost exactly 100 MPG. I have been told that other 4 stroke engines get between 185 and 200+ MPG and am really curious.

Danny, you must have a serious leak in your fuel line. There is no way a GSX 50 shouldn't do 140 mpg. Also I find that, contrary to what is written above, 98 octane goes further and better than the low grade fuel. Am I imagining this?

 

[Danny3xd]

John, No leaks but did spend a lot of time running the engine and not the bike during the GB saga. Not any where long enough to use that much fuel, I don't believe, but... Is noticeably better now by sight and think the GB was hanging up and could be the cause of poor efficiency. Was going to recheck consumption starting today. (Just so dang happy with it, pretty much just spend every spare minute ridding and fill up with out noting use)

I was wondering about octane and wanted to ask you John. The manual says " This engine is certified to operate on unleaded gasoline with a
pump octane rating of 86 or higher (a research octane rating of 91
or higher)." But does seem happier on higher. I was thinking I just felt better giving the baby the best and at our consumption and a few pennys more what does it really hurt? Even if it is just in my head.

I have the Honda GX50. I thought above was a typo then googled it.

John, side note; I think I have read every post you have written and want to thank you for sharing your knowledge and for all the time you and every one on that thread spent helping me with my GB problem. I really was ready to throw in the towel. ...and you guys weren't.

 

[Irish John]

Thanks Danny for your kind words. I too have been helped so much by MBc members. Especially the older ones. I'm not sure if using 98 octane petrol in my Honda GXH 50 is a waste of money or even bad for it. I doubt the comment above that implies it is harmful to the motor but there are guys here who will know for sure and one of them will probably soon advise us.
I do know that fuel with ethanol in it is bad for the Honda and the Honda handbook warns against its use. Also petrol companies are known to vary the amounts of ethanol to amounts that are really harmfull. I filled my car with one half tank of ethanol fuel and it wrecked the fuel lines and hosings and caused $1100 damage after just half a tank. The mechanic said it was like putting sugar in your tank which has long been a way of wrecking a motor instantly.

 

[Danny3xd]

Wow! That is great information and I missed it! Read the manual many times too.


"You may use regular unleaded gasoline containing no more than
10% Ethanol (E10) or 5% Methanol by volume. In addition,
Methanol must contain cosolvents and corrosion inhibitors. Use of
fuels with content of Ethanol or Methanol greater than shown
above may cause starting and/or performance problems. It may
also damage metal, rubber, and plastic parts of the fuel system.
Engine damage or performance problems that result from using a
fuel with percentages of Ethanol or Methanol greater than shown
above are not covered under warranty."

http://www.honda-engines.com/Engines_owners_manuals/ownersmanuals/37Z4C603.pdf

Not to ramble to far off topic and please forgive this. At last years East coast rally, I pulled up with a flat on my MB. Before I got the bike off the car, 6 people who I met 2 or 3 minutes before were helping me swap out the wheel. Was amazed. Good folks

 

[Nitrohorse]

I will never approach 175mpg. If I was cruising around at 20 mph or lower, maybe...or if I weighed less than 220 lbs....but I don't see either happening any time soon.

Houghmade,
Don't look at your weight as a hindrance, but look at it as more of a benefit.
Both you and I are more "aerodynamically designed" with a "rounded torso" which allows for better airflow at higher speeds...ha..ha.
Plus, we can ride our bikes in gale force winds and still maintain the rubber to the road contact.....

 

[bamabikeguy]

Houghmade,
Don't look at your weight as a hindrance, but look at it as more of a benefit.
Both you and I are more "aerodynamically designed" with a "rounded torso" which allows for better airflow at higher speeds...ha..ha.
Plus, we can ride our bikes in gale force winds and still maintain the rubber to the road contact.....

I have a whole new group of MBidjuts doing this for EXERCISE, all have 7 or 21 speed cruisers, and ther retiree group used to go walking around in circles at the local mall and gym.

Now they are out there on these bikes, constantly peddling, topping hills wide open throttle....one told the local newspaper he lost 12 pounds in one month.

 

[Irish John]

I will never approach 175mpg. If I was cruising around at 20 mph or lower, maybe...or if I weighed less than 220 lbs....but I don't see either happening any time soon.

Then there is the added advantage of knowing that when you run out of petrol the sheer momentum of the mass velocity will carry you to the next service station. Also we can't be considered mere lightweights when it comes to motored bicycle matters!

 

[HoughMade]

Houghmade,
Don't look at your weight as a hindrance, but look at it as more of a benefit.
Both you and I are more "aerodynamically designed" with a "rounded torso" which allows for better airflow at higher speeds...ha..ha.
Plus, we can ride our bikes in gale force winds and still maintain the rubber to the road contact.....

Dude, I'n 6'3"- I'm no beanpole, but 220# at 6'3" ain't exactly electric cart at the Walmart territory.

 

[Terminal Velocity]

low vs. high octane fuel

...I'm not sure if using 98 octane petrol in my Honda GXH 50 is a waste of money or even bad for it. I doubt the comment above that implies it is harmful to the motor but there are guys here who will know for sure and one of them will probably soon advise us
...

I think it depends on how you define waste. If you mean you lost money/performance then nah. I doubt it. If you mean waste as didn't gain in performance then probably. A major factor in determining engine efficiency is in the compression ratio. I checked wikipedia (not that its always right, but anwyway) and the research octane rating cited and minimum octane rating (what you see at the pump) are basically two different representations of the same thing. You'd have to read the article to understand why. Anyhoo, the higher the compression of the gas/air mixture in the cylinder, the hotter the gas gets on compression (this is why diesels don't need spark plugs...I also demonstrate this principle to my students using a piece of toilet paper in an airtight clear acrylic syringe designed to show just that. When the syringe is compressed quickly all the way to the bottom the paper burns in a bright flash!!). What you don't want is for the gas to ignite before the optimum position in the cycle. So, the lower the octane the easier it ignites, the higher the octane the more difficult it is to ignite. Therefore, if the engine is designed to operate on the low octane fuel, it is low compression and the higher octane fuel does not improve engine performance. Engine performance is only decreased when the gas pre-ignites causing all that knocking. Also consider the energy density of 1 drop of gas...its basically the same for both high and low octane, which is why you won't get a performance boost...its the compression that has the ability to more efficiently extract energy. In short, there is likely little if any increase in engine performance if you use the high octane fuel instead of the low octane fuel and there is no practical reason why it would be harmful. I suppose they may put MORE detergents in the high octane stuff, but that's easily remedied with a bottle of carbureator cleaner...just add a tablespoon once in a while when you fill up. You'll save money that way AND you'll know what you're putting in your engine.

Personally, I use the cheap stuff for the basic reasons as stated above. Here's a thought, in the heat of summer if you're running your engine hard, it may be helpful to use higher octane gas if the engine is running hot...but that's only a maybe. I've never noticed any problems on hot days, but it might be worth a try.