CTX 700 Forum banner
1 - 20 of 49 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter · #1 ·
I just filled up for the second time - first time to calculate mpg (Dealer had put in about 1/2 tank so couldn't figure the first tank).

In 140 miles, 50-50 mix of highway/suburban roads - used 2.1 gallons 87 octane for about 67 mpg. Mostly regular D mode with a little Sport mode thrown in where applicable;).
 

·
Registered
Joined
·
4 Posts
I just filled up for the second time. First take was from dealer not sure what grade it was. I would guess 87. Since then I have put in 92 non ethanol.

I am riding the naked model CTX700N.
Last tank was 167.7 miles and 2.25 Gallons for 74.53 MPG.

First take I calculated around 70 MPG, however I did not look first to see how full the take was so I was able to fill it to same point for apples to apples comparison.

Mostly this is a 65/40 highway/city driving. And I am shifting late according to manual but bike seems to have great power around 3k RPM and that is how I like it.
 

·
Premium Member
Joined
·
795 Posts
Fireman 63, I am getting great numbers too.

Last Sundays ride I had 720 miles on my CTX700n and rode at 50-60mph speed on 2 lane river road most of the miles. Went 120.6 miles on 1.834g so 65.7 miles per hour.
Trip home and round the foothills (bike now at 948 on odometer) and I went
160.2 miles on 2.124g so that is 75.42. Again speed around 50-60mph riding. I did have the windshield on bike. I think I am running it more between 3 and 4k on tach more. It maintains speed in 6th around 60mph and + but no rapid speed change to pass someone without dropping to 5th (could go to 4th but I don't think I have to in most cases), then passing at 60 is much better.
 

·
Registered
Joined
·
975 Posts
I just filled up for the second time. First take was from dealer not sure what grade it was. I would guess 87. Since then I have put in 92 non ethanol.

I am riding the naked model CTX700N.
Last tank was 167.7 miles and 2.25 Gallons for 74.53 MPG.
I hope not to start too much of a debate here but does anyone believe there is any advantage to running a higher level of anti knock octane grade than is recommended from the manufacturer? Lots of people run higher grades, so I'm just wandering if there is anything to it, or is it just a waste of money?

Everything I've read from the experts state that one should run no higher than the recommendation. For example, if the OEM calls for 87, then I should use 87 or higher but that there is no need to go higher as long as at least 87 is available. I don't mean to come across as an expert, I'm actually asking this humbly, because I'm not an engineering-minded person and would really like to know what others think on this matter that understand technology better than I do.

As for non ethanol, pure gas, I'm a believer. I've done some anecdotal testing, running a few tanks of pure gas and noting the mpg, switching to a few tanks of E10, then documenting the mpg; and then back to pure gas and documenting again; In my little, not-very-scientific test, the mpg increase of pure gas in a couple of different vehicles has been almost 3%. Where I live, however, even though one can find pure gas at one or two places in every town, he or she will pay a little more than the cheapest prices available, and thus it's not really a savings economically, but it is a way to increase mpg if one is in to that sort of thing like I am.

I've noticed that in some areas of the country though, that pure gas is not even available and it can be hard to find everywhere. The scarcity of pure gas can be blamed on a 2007 law passed by Congress called the Energy Independence and Security Act. This law requires that fuel distributors blend a minimum amount of ethanol or other renewable fuels into gasoline and this minimum amount goes up every year by law. I think that this part of the law is called the Renewable Fuels Standard (RFS); and it is kept track of by a system called RINs.

Not to get too political, but basically what has happened is that, in the creation of the law, it was expected that the use of E85 would drastically increase by now, because GM, Ford, Toyota, and Chrysler had produced millions of flex-fuel vehicles that can accept E85. Also, at the time the law was passed, it was expected that cellulostic ethanol would soon be available. In both cases, however, not much has happened. No real break throughs in cellulostic ethanol and not much interest in E85 by consumers mostly because most people can do simple math in calculating the price versus range loss of E85. So now the distributors have to meet the renewable fuel standards while working mostly with only E10, thereby making almost all of our gas E10.
 

·
Registered
Joined
·
842 Posts
Fourth tank full, and 66 mpg. Mostly Auto mode. I find the shift points in Sport to be way too high, especially 4,5,6. With wide open throttle, A mode shift points are aggressive enough.
 

·
Registered
Joined
·
90 Posts
I'm averaging between 72 and 75 mpg, though my next fill will be the first with the top case in place.
 

·
Premium Member
Joined
·
795 Posts
Effem Tee, you get only D and S (S=sport I think) plus MT for manual.

Have you run a tank of gas entirely in one mode or the other on a similar ride. That would tell you basically save in the lessor power band.

I don't have the DCT but with over 1100 miles I find 4 5 6 gears have less response to the throttle as do the lower gears. This is because the engine load is more as the rpm's drop. The fact you are getting less miles per gallon is what I found when I used higher shift point. Now I am running lower rpm shift point and lower rpm cruising. My MPG has gone up and I am still ok with the acceleration I experience and know to down shift to get the power back when I need to pass. 5 and 6 gears are used at slower speeds as long as not going up steep hills under 50. Very pleased with mpg.
 

·
Registered
Joined
·
34 Posts
I haven't calculated my MPG yet for my bike but I have been been using 89 octane gas since I got it. And have been averaging about 190-200 miles a tank, with me being kinda "peppy" on the throttle.
 

·
Registered
Joined
·
975 Posts
I haven't calculated my MPG yet for my bike but I have been been using 89 octane gas since I got it. And have been averaging about 190-200 miles a tank, with me being kinda "peppy" on the throttle.
Are you sucking it pretty dry at that range, or do you have some fuel left in the tank?

That's about the same real-world range I have on my scooter, and it's got a slightly larger tank @ 3.4.
 

·
Registered
Joined
·
58 Posts
Discussion Starter · #12 ·
3rd tank on the CTX700N DCT- 155 miles of mostly around town/suburbia - very little open highway this time - still about 67 mpg on 87 octane. With a tank so small, a little variation in the fill line makes a big difference.
 

·
Registered
Joined
·
34 Posts
Are you sucking it pretty dry at that range, or do you have some fuel left in the tank?

That's about the same real-world range I have on my scooter, and it's got a slightly larger tank @ 3.4.
It was pretty low, there was barley any gas left but I probably could have gotten more miles out of it if I wasn't sure I was about to pass the last gas station for about 50 miles lol.
 

·
Premium Member
Joined
·
795 Posts
It was pretty low, there was barley any gas left but I probably could have gotten more miles out of it if I wasn't sure I was about to pass the last gas station for about 50 miles lol.
I left the house with 3 bars showing on gas gage and went 60 miles and still had 2 bars left and no flashing yet. This has got to be my first bike where I feel that gas is not an urgent thing anymore.


The tank holds 3.28 gallons so when you fill up at say 150 miles and it take 2.28 gallons then you have about a gallon of gas left in the tank. So you have been getting 65.7 miles per gallon to go the 150. That gallon remaining should take you at least another 50-60 miles so if you know you only have 30 miles to go back into town you can relax and just ride.
 

·
Registered
Joined
·
34 Posts
I use 89 octane and don't have an issue with it.

If my memory serves me correctly the owners manual says minimum of 86 octane for the bike.
 

·
Registered
Joined
·
975 Posts
any benefit to using 91 or even 94 octane?
As a disclaimer to the post below, I'm by no means someone who understands engine technologies or physics in any way, but I have researched octane levels somewhat.

I posted my opinion earlier in the thread about using anything above 87 octane in the CTX700. In short, I think it is a waste of money based on what all the experts say.

This time around I'm providing a link to what the Federal Trade commission has to say about using octane over and beyond what the owner manual recommends...

Paying a Premium for High Octane Gasoline? | Consumer Information

excerpt: Unless your engine is knocking, buying higher octane gasoline is a waste of money. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.

It may seem like buying higher octane “premium” gas is like giving your car a treat, or boosting its performance. But take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage, or run cleaner. Your best bet: listen to your owner's manual.

The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.

What are octane ratings?
Octane ratings measure a gasoline's ability to resist engine knock — a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane), and premium (usually 92 or 93). The ratings are posted on bright yellow stickers on each gas pump.

What's the right octane level for your car?
Check your owner's manual. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knocking.

How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.

Will higher octane gasoline clean your engine better?
No, as a rule, high octane gasoline doesn’t outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. In fact, the U.S. Environmental Protection Agency requires that all octane grades of all brands of gasoline contain engine cleaning detergent additives to protect against the build-up of harmful levels of engine deposits during the expected life of your car.

Should you ever switch to a higher octane gasoline?
A few car engines may knock or ping even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair. After that work is done, go back to the lowest octane grade at which your engine runs without knocking.

Will knocking harm my engine?
Occasional light knocking or pinging won't harm your engine, and doesn't mean you need a higher octane. But a heavy or persistent knock can lead to engine damage.



I've read very similar information from other sources. Some sources even state that using higher-than-recommended octane can create more pollution or can make your exhaust-treatment systems work harder to fight tail-pipe emissions, however, I'm not sure this is true. I am convinced, however, that it certainly has no benefit, and that we should take into account that Honda has sacrificed building us a more performance-oriented machine to give us something that can use a lower octane, cheaper fuel, and that we should take advantage of this benefit of this MC. For instance, my current scooter was designed to be more precisely-tuned, higher compression, and have higher performance per cc, and therefore requires premium; but I'd much rather have a more regular engine, that uses regular gas, and is designed to go the distance. That's what Honda has given us in the 670 cc power plant.

Now for the things you can do fuel wise to increase mpg, performance, and reliability: (1) Use fuel from retailers that offer Top Tier gasolines, which is a higher detergent level recommended by engine manufacturers to fight fuel-system deposits (see www.toptier.com); (2) If available, and you want to increase your mpg and reduce the chance of water absorption in your fuel during periods of storage, use pure gasoline instead of the regular E10 ethanol-fortified fuel; and (3) Make sure you don't run your vehicles on old stale fuel unless stabilizer was used; and (4) Replace fuel filters regularly.
 

·
Premium Member
Joined
·
795 Posts
Page 42 states 86 or higher. Most common here is regular 87 Octane.
My take on octane is to use 87 because it is the most used fuel. The stations sell more of it and it is by far the freshest gas you can get. Gas does go stale like beer. lol

octane knock (detonation) can damage an engine but I don't thing this engine was designed around higher octane so I do not worry at all about it. Honda has designed more engines than any one on any forums I have read.

I am just stating my usage and why. It's a free country, spend more if it makes you happy.

another example, I have a very high performance supercharged car that calls for premium. I often run regular (about every other fill up) as it sits a lot and I want the freshest gas so it last longer before going stale. I don't worry about engine detonation as I rarely drive it at the redline of 6500rpms (that is 90mph in 3rd gear and it has a 6 speed). Driven only 27k in 9 years I don't believe my practice is hurting it. I log when I last drove it and I never let it sit more than 30 days.
 
1 - 20 of 49 Posts
Top