Poor fuel economy 2009 VFR 800

Hi all,

I recently got my hands on a showroom condition, 2009 VFR 800 with only 3000 miles on the clock in beautiful pearly white having dreamed about owning one for years. I’ve been riding it for a few months now and on the whole it is an absolute peach. It feels amazing, looks amazing, it’s so smooooooooth… it almost sounds amazing, i’ll be venturing into the aftermarket exhaust arena soon… but overall I love it!

My one issue so far is fuel economy.

I know these aren’t the most super frugal machines on the market but as far as my research shows I should be getting towards 40 MPG (200 miles to the tank) but according to my calculations I’m getting more like 25-30 MPG (under 150 to the tank).

Obviously, for the first few weeks I was just enjoying the bike and enjoying wondering into the v-tech section of the rev range so I wasn’t paying much attention to fuel economy and when I did notice how frequent my fill ups were I just blamed my ham-fisted, trigger-happy right wrist so didn’t think much of it.

However, I thought I’d try an experiment and fill her right up to the brim and ride a whole tank really conservatively to see what the best figures I could get were and I’m shocked by the results. I was very strict with myself and made sure to do all the common sense things to improve MPG - waited for the bike to be warm before riding, always accelerate gently, keep the revs between 3k-5k, cruise in whatever gear keeps my revs just above 3k, planning ahead and coasting up to lights where possible & safe, avoided carrying extra weight etc etc…

I did this over 2 tanks with exactly the same result: the absolute best figure I got was 32 MPG!!!

All of my riding on this bike so far has been in commuting in town so I fully accept that I won’t be getting the best MPG possible but this seems low enough that it must indicate that something’s wrong, no?

I’ve read around on all the forums and have ruled out the common problems that have been mentioned - thermostats stuck open, low tyre pressures etc. as they don’t seem applicable. The bike has only just ticked over 4000 miles so the bike is still really young. Engine coolant temp tends to read around 80 C when the going is good and up to 104 C when the fan kicks in stuck in traffic.

I’m going to take it into my garage but any ideas of where I should point them to so they don’t charge me a load for ‘diagnosis’?

BTW the bike is totally stock and has been only serviced by Honda garages so far.

Thanks in advance

 

Welcome from the colonies, PW8! That is THE colour scheme that I really like for the 6th gen.

I have two questions for you: one simple and one delicate:

1. your bike has the stock exhaust, so this isn't too likely, but does it have a Power Commander? Mine costs me about a 10% fuel economy hit.

2. are you little or big? Those of us who are not eligible to be jockeys also pay a fuel economy price.

 

And for you Americans out there, please remember that PW8 uses gallons that are 25% larger than those of the Excited States.

 

Hi DH,

Nice to meet you.

1. Nope, no PC on board.

2. Yes I suppose I'm on the larger side. 6ft2 and...um...of healthy appetite? Think rugby rather than football (soccer) haha

Also, yes thanks for clarifying, my initial post was in Imperial units

 

Well, I am decidedly far closer to football (US, lineman) than football (UK) sized and get about 35-40 mpg (real gallons) with a PCIII (love the open Leo Vince exhaust sound) when I ride as hard as I'd like. Longer highway runs yield better fuel economy. I am by no means a mechanic, so I don't have a solution for you. Sorry.

Are you actually in London, or further out? Last year I was really lucky and did a combination Goodwood Festival of Speed and British GP trip with my son. I really wished that I had my VFR on that trip!

 

You noted in your post that you spend a lot of time commuting in town. In town commuting can be especially hard on fuel economy as no matter how you slice it, you spend a lot of time accelerating from a stop.

I offer up a few stats for own bike. My 2000 VFR800 is all stock with the exception of an 18" Delkevic slip-on exhaust. I am 6'-1" tall and 175 pounds and I thought it might be pertinent for weight comparison.

When I commute back and forth to work my usual distance would be less than 10 km's (one way) and there are about 10 stop lights (depends on route I take to work) and the average speed would be 60 km/h. On average, when I fill the tank I use about 8 litres per 100km's. My bike will often see temps in the summer time of around 102-105 *C when stuck in traffic, which is nearly impossible to avoid. Kelowna is a tourist town with one Main Street running straight through the middle of town. When out on the highway the fuel economy is closer to 5 litres per 100 km's.

Using the Imperial gallon this works out to 35 mpg city and 56 mpg highway. Naturally my mileage goes down depending on the amount, and the urgency with which, my right hand applies throttle. I have seen as low as 25 mpg in town if I'm in a hurry to get to the next stop light. LOL

 

I can only speak about the "Small" gallons we have in the US. My 2007 is completely stock. I run Amsoil 10w 40 synthetic. I am 6'2" and 260 lbs. When my bike was new it got 32 to 35 mpg no matter how I drove. My first 40 mpg came when I was over 8000 miles. I started to get 40 to 44 all the time on the highway only after 10,000 miles. These engines are built very tight. They take a l-o-n-g time to break in. For some reason I get my best mileage with the factory bags installed and loaded. But this usually means I am on a multiple day road trip. I tend to ride the back roads as much as possible.

I think trying to keep the rpm around 3000 is too low. Bike is working too hard. Try keeping the rpm between 4000 and 5000. Remember this bike redlines at 11750 rpm. Let her breathe and be patient, your mileage will come in due time.

 

Might be a stretch but I bought a 2004 VFR800 in showroom condition with only 2.5k miles on it. It got horrible mileage and I later discovered the engine was completely shot from sitting idle for so many years. Even still, when I put new plugs in the bike gets 40mpg pretty much everywhere. This goes down as the spark plug in cylinder #4 oil fouls over time.

Have you checked the condition of your plugs?

 

:welcome: to the madness :wave:
Glad to have you and glad to see many have chimp in to help.....Please carry on :thumbsup:

 

Found if I stay out of the vtec and just keep it cool on starts and just cruise..I get about 190 miles to a tank...but when Im on it...tearing up the nice roads out here it drops to around 130. Also weigh 165

 

I have an '09 as well and I used to get close to 200 miles out of the tank pretty consistently when I first got her, but after putting a PCV and K&N filter on (she had a 2Bros exhaust when I got her), it went down slightly (15-25 miles less per tank). I ride the '09 mostly for commuting so I did the same experiments as you and found that by staying under the VTEC RPM and being conservative with the throttle, I could get closer to the 200 mile mark, but not always. However, after the last tune up, oil/filter change (Rotell T6), clean air filter and new sparks plugs (NGK Iridium), I started getting more consistently closer to the 200 mile mark. But, there were a few times where I got less than 160 after the tune up and I thought that was really strange and started to get a bit worried. That was until I was going on a long freeway ride that I noticed that my speedometer was jumping all over the place! 85 mph, 120 mph, 0 mph, 58 mph, etc. turned out that my speedometer sensor was going, or at this point had gone bad. I did a 200+ mile loop and my ODO only read about 27 miles! You may want to peek now and then on the speedometer to see if it's "jumping" at all, as this will throw your mileage off pretty good. Again, I noticed the mileage drop at first, but not the speedometer jumping until the one long ride when I knew I was a lot further than the ODO was showing. It was only by looking at the dash longer than just a glance that I noticed it, kind of hard to do in traffic, so I recommend only doing while on an open road!

Another thing to throw out and possibly experiment with, is octane. Not sure about the UK, but we typically have three different octane rating fuels at most gas stations, 87, 89, 91/92. I tried all three and found that it didn't make too much of a difference which one I used, maybe a few miles or two, but several people have found using one grade over the other improved their mileage a greater deal. BTW, I ended up going with 87 and for reference I'm 5'8, 165-175 lbs with gear, depending on commuter (textiles) vs. "spirited" gear (leathers).

 

What temp are you showing when riding ?? About 190 ?? Two possible and not uncommon fuel-wasters are bad thermostat or bad engine temp sensor or both.

 

I have a totally stock '09 as well and your mileage seems off. You're a much bigger dude than me (I'm 5'10" and a starving graduate student), but honestly that shouldn't make a huge difference in mileage. I easily get 200 miles to a tank, and my mileage on the highway is usually 45-50 if I keep it to 65 MPH, dropping to the low 40s if I am riding 70-80. Even in town I still get close to 40 mpg.

I have a few suggestions but they're very, very anecdotal. I found that when switched up gasoline, I swear my bike would guzzle through gas faster sometimes (not always). It also seemed to always get better mileage when I used Chevron, so I figure hey screw it I'll just stick with Chevron. My scientific training tells me that it is very unlikely that this matters to a noticeable degree for mileage, but hey.

Other suggestion is to check your air filter (is it super dirty?) and tire pressure. I'm sure you probably have, but can't hurt to make sure. Good luck!

 

I ride 100 miles round trip to and from work daily. If I ride between 55 - 65 mph my bike get between 42 - 46 mpg.
If I run between 75 - 85 it gets between 32- 36 mpg. The best I've gotten is 48 mpg. The worst is 29.
My bike is well maintained and cared for. I bought my bike new. My mileage got better around 8000 miles. Give it time , you don't have many miles on it yet.
Also if your running 10% ethonal fuel your mileage will be effected. Find a fuel station with non ethonal fuel and I'll bet you will see a difference.