re gas mileage

[bmwlarry]

I am 6,000 miles into our Spyderfest ride. Traveled from Oregon to PA and are now in Illinois. I use the cruise a LOT to help with wrist/grip fatigue. A friend called me and told me that he heard that when cruise is on & set, the engine power is cut somewhat by the computer reducing MPG. He stopped using cruise and is getting better MPG. Doesn't seem to make much difference for me. Any truth to this??

[Phyxius]

I don't understand how that is mechanically possible?

I used cruise for about 1100 miles on the way home from spyder fest up and down mountains for a good bit of it too, I was getting what I think is pretty good gas mileage - check it out here:

https://www.fuelly.com/driver/phxyiusspyder/spyder-rts

[boborgera]

I don't understand how that is mechanically possible?

I used cruise for about 1100 miles on the way home from spyder fest up and down mountains for a good bit of it too, I was getting what I think is pretty good gas mileage - check it out here:

https://www.fuelly.com/driver/phxyiusspyder/spyder-rts


I think the last sentence in Lamont's signature, Sums it up well. ;)
[a friend said he heard]

[Bob Denman]

He might just be getting better mileage because he's thinking about it a bit more... :dontknow:

[ARtraveler]

As long as you have the :spyder2: in a gear where it is not lugging to increase speed--you should get equal or better mileage with the cruise control engaged.

I find no difference with mileage either with or without cruise control engaged.

[2 Cruysyn]

Interesting question.

Of the 916 miles I tracked to and from Spyderfest I averaged 27.62 MPG. My worse was 22.57 fighting cross and head winds. My best was 30.42 earlier on the same day when I'm pretty sure, and the only time during the trip, I used the cruise.

Another thing I found interesting is that on the way to Springfield, on I-44, my RPM was generally in the 6200 range +/- and I still got 29.53 MPG.

[Chupaca]

the only thing I see that could make that kind of difference would be hilly terrain where the cruise control raises rpm slowly to maintain set speed. If you do it manually the rpm's go up faster... :dontknow:

[Illinois Boy]

Another thing I found interesting is that on the way to Springfield, on I-44, my RPM was generally in the 6200 range +/- and I still got 29.53 MPG.

In that range you are getting nearly the best ratio of "power-to-fuel" being burned for the Rotax.

In other words; fuel being burned at that range is right in the pocket where the maximum power (torque) is delivered by this Rotax engine -- thus you did not lose fuel efficiency in that range, but rather gained efficiency -- as compared to a lower rpm range.

Now... let the arguments and debates begin...:thumbup:

Oh yeah... about the cruise control. Fuel efficiency can vary between manually shifting and using cruise control. I wouldn't lose sleep over it. But if you are, you might be best to manually shift when there are more variances in the road's terrain; or if there are other factors, such as headwinds -- otherwise your Spyder may lug itself up and down and into the wind causing it to run in gear-to-rpm combinations that are not the most efficient for power -- thus affecting fuel consumption. It appears some people turn-on the cruise control and then forget they have to pay attention to their Spyder's engine and gear placement... which is a "no no"...

Lastly, have never heard of anything on the Spyder that slows-down the engine with cruise control on. Might be... but seriously doubt it. Just my one-cent...

[Bob Denman]

Another thing I found interesting is that on the way to Springfield, on I-44, my RPM was generally in the 6200 range +/- and I still got 29.53 MPG.
That's got to be up around 85mph... :shocked: :bowdown: :firstplace:

[Bob Ledford]

I have NOT been in hill country with our Spyder as of yet. I can only relate what I know or would anticipate to be factual. When we were on our GW (88) when we started into hill country the cruise control was turned off. I found my right hand to be smarter the the CC I would take advantage of down hill momentum and smoother uphill throttle control plus the fact that if a down shift was called for I could do it before the engine bogged down and would go wide open to maintain the last speed setting

The human brain and eyes are sometimes the ultimate economy machine when compared to the on board CPU.

[NancysToy]

It never ceases to amaze me about the "facts" that people hear to be true. I guess that is how urban legends get started. Not sure why your friend got worse mileage on cruise, mine is always better that way. I guess I'm using it wrong. ;)

[Bob Denman]

I would take advantage of down hill momentum and smoother uphill throttle control plus the fact that if a down shift was called for I could do it before the engine bogged down and would go wide open to maintain the last speed setting

The human brain and eyes are sometimes the ultimate economy machine when compared to the on board CPU.
:agree: :thumbup:

[SPYD1]

Sounds like a case for "Mythbusters". They proved that gas mileage is not improved by leaving the tailgate of a truck down.

[Phyxius]

I already commented on the gas mileage thing but wanted to mention a bit more about my using CC in mountains.

So, prior to this trip I never really used the CC. I don't really use it in my car or truck either, unless I catch myself speeding a lot in which case I'll use it to make sure I stay close to legal. On the way to SF I used CC to keep the group's speed consistent as the lead was using CC.

On the way home I was the lead and used the CC to prevent speeding. My thought was to turn it off when I hit the mountains but it did an AMAZING job of keeping speed steady both up and down the mountains?! I was shocked. My car can't even handle a little hill here at home if CC is on. So, the other day I tried CC on the spyder here at home and it sucked almost as much as my car on the little hills.

So, I don't understand it but the Spyder CC kicks butt on mountains but won't be used at home.