My initial thoughts

[oldqwerty]

Originally Posted by Huck369

took the RX-3 for a loop by Wolfe Creek Dam, around Lake Cumberland Saturday, and got 79 MPG out of it, was running 45-55 mph most of the day...191 miles on 2.39 gallons ...my best MPG so far, all other fill-ups have been in the Mid 60's

I wasn't liking the seat to much by the end of the day....might need to get one of those Sheepskin covers....

Most of the intended use with my Cyclone will be cruising around 55mpg on paved rural roads. 79mpg sounds really good. Is there ethanol in your fuel?

[Weldangrind]

Originally Posted by Huck369

I wasn't liking the seat to much by the end of the day....might need to get one of those Sheepskin covers....

I'm curious about reupholstering a seat with a gel pad; I wonder if that would be a good solution.

[Huck369]

Originally Posted by oldqwerty

Most of the intended use with my Cyclone will be cruising around 55mpg on paved rural roads. 79mpg sounds really good. Is there ethanol in your fuel?

Yes, there is 10% Ethanol in our fuel, and that was running Regular, 87 Octane fuel.

[Huck369]

Originally Posted by Weldangrind

I'm curious about reupholstering a seat with a gel pad; I wonder if that would be a good solution.

I have a Gel Pad, I took it with me, and threw it on the seat toward the end of the day...it helped a little, but didn't really fit the seat well...so...maybe...?

[woodlandsprite]

Originally Posted by Weldangrind

I'm curious about reupholstering a seat with a gel pad; I wonder if that would be a good solution.

Someone on another forum did this with a spare seat they obtained from csc. Not sure if they have put many miles on it yet... They were able to salvage the stock seat cover for reuse in this application. When I'm not on a mobile device I'll go grab a link.

[woodlandsprite]

Link to the other forum where they discuss the mod: click here

[Weldangrind]

Thanks for the link. It even has a link to Amazon, where the OP purchased the gel pad. I like how he contoured the foam and changed the angle, so as to position himself further back. Smart!

[woodlandsprite]

update on this - that OP has decided to scrap the gel pad, and is having a custom seat made.

[oldqwerty]

Originally Posted by Huck369

Yes, there is 10% Ethanol in our fuel, and that was running Regular, 87 Octane fuel.

My work in biofuels research averaged a ~17% improvement in fuel efficiency when E0 replaced E10 of identical octane rating (R+M)/2.

[Weldangrind]

Interesting findings. I presumed the mileage figure would drop with a higher octane level, but I hadn't considered that mileage would improve with an identical octane number.

Do you recall what the final octane level was in those tests? I presume there would be a sweet spot for the average car or truck.

[oldqwerty]

Originally Posted by Weldangrind

Interesting findings. I presumed the mileage figure would drop with a higher octane level, but I hadn't considered that mileage would improve with an identical octane number.

Do you recall what the final octane level was in those tests? I presume there would be a sweet spot for the average car or truck.

We tested gasolines from 82.3 to 106 octane (R+M)/2, diesel fuels with cetane numbers from 38 to 62, and other fuels with octanes up to 117. The happy sweet spot for all vehicles not specifically designed to run on pure biofuels is 0%.

It is impossible to recalibrate an engine to run as efficiently per unit volume on 100% ethanol or in any % mixture with gasoline because ethanol only has 5/8 the potential energy per unit of volume as gasoline.

To make matters worse, engines operated on nonimiscible fuel mixtures cannot be tuned to maximum efficiency for BOTH fuels, so efficiency of one fuel will be sorely compromised. In the case of gasohol, the ethanol does not contribute to forcing the piston down until well after the beginning of the power stroke, and typically is still burning well into the exhaust stroke, which is kind of like two riders on a tandem bicycle, and the one in the back has the brake on to keep the bike from rolling backwards. Therefore, poor combustion efficiency compromises fuel efficiency.

Also, the additives that allow immiscibility occupy fuel volume and not only do not burn, they inhibit burning. Sort of like replacing a little of each intake charge with a tiny burst from a fire extinguisher.

These are the reasons why theoretically E10 has about 97% of the potential energy of gasoline, but in the real world only provides 73 to 89% of the power and efficiency per unit volume.

[SpudRider]

Egads! I hate how the government is always screwing things up.

Thanks for taking the time to compose, and post this useful information. I think I am going to start filling up at the one gas station in town which pumps fuel without ethanol.

[oldqwerty]

We have not had a government for quite some time now. We are ruled by a self perpetuating bureaucracy. According to the Declaration, "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.--That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, ... ." Just try withdrawing your consent. Go ahead, just try.

[Weldangrind]

Originally Posted by oldqwerty

We tested gasolines from 82.3 to 106 octane (R+M)/2, diesel fuels with cetane numbers from 38 to 62, and other fuels with octanes up to 117. The happy sweet spot for all vehicles not specifically designed to run on pure biofuels is 0%.

It is impossible to recalibrate an engine to run as efficiently per unit volume on 100% ethanol or in any % mixture with gasoline because ethanol only has 5/8 the potential energy per unit of volume as gasoline.

To make matters worse, engines operated on nonimiscible fuel mixtures cannot be tuned to maximum efficiency for BOTH fuels, so efficiency of one fuel will be sorely compromised. In the case of gasohol, the ethanol does not contribute to forcing the piston down until well after the beginning of the power stroke, and typically is still burning well into the exhaust stroke, which is kind of like two riders on a tandem bicycle, and the one in the back has the brake on to keep the bike from rolling backwards. Therefore, poor combustion efficiency compromises fuel efficiency.

Also, the additives that allow immiscibility occupy fuel volume and not only do not burn, they inhibit burning. Sort of like replacing a little of each intake charge with a tiny burst from a fire extinguisher.

These are the reasons why theoretically E10 has about 97% of the potential energy of gasoline, but in the real world only provides 73 to 89% of the power and efficiency per unit volume.

That was an excellent explanation.

I realize that I failed to ask my question properly. I knew that Ethanol only has a fraction of the potential energy of gasoline, but I thought the number was closer to propane, which I think is around 80%. In Canada, we went through these issues in the '80's, when our gov't offered rebates to those who would have propane conversions performed. The only reason that propane seemed to be more efficient was that is was far less expensive than gasoline in the beginning. Then the price started creeping up...

The question I meant to ask was, is there an octane sweet spot for straight gasoline for modern cars and trucks? I ask that knowing that some vehicles require premium, but I'm not interested in that info. I'd like to know your thoughts about everyday passenger vehicles that run on regular.

[oldqwerty]

Originally Posted by Weldangrind

That was an excellent explanation.

I realize that I failed to ask my question properly. I knew that Ethanol only has a fraction of the potential energy of gasoline, but I thought the number was closer to propane, which I think is around 80%. In Canada, we went through these issues in the '80's, when our gov't offered rebates to those who would have propane conversions performed. The only reason that propane seemed to be more efficient was that is was far less expensive than gasoline in the beginning. Then the price started creeping up...

The question I meant to ask was, is there an octane sweet spot for straight gasoline for modern cars and trucks? I ask that knowing that some vehicles require premium, but I'm not interested in that info. I'd like to know your thoughts about everyday passenger vehicles that run on regular.

87, unless at high altitudes. 85 at high altitudes. Make sure the octane rating is (R+M)/2. Some places use different definitions of "octane rating."

Many engines loose power and efficiency as octane ratings go up because the slower flame front propagation does not allow peak cylinder pressure early enough in the combustion stroke.

Tdub (stock engine with rejet) lost power slightly over 88 octane, exponentially.

Tdub2 (267cc EFI, 11.6:1 compression, timing advanced 4* with ping sensor and ignition retard to run 87 when necessary) gains power with up to 97 octane, then levels off.

Pirate (276cc carbed, 12.7:1 compression) requires 93, and really likes 103. My son put 87 in Pirate, rode 1/4 mile, shut the bike off and pushed it home. It pinged so bad he thought he had blown the engine.

To vary octane we started with 87 E0 and added toluene, a common octane booster and paint thinner.