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rfmueller

Mileage Dropped

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rfmueller

In October I replaced the spark plugs with OEM, balanced the throttle bodies, and replaced both worn out stock tires with Michelin Pilot 4s.  Since then the gas mileage has consistently been down by over 5 mpg.  It was always a little over 65 mpg city or hwy or both even during the cold months.  Now, it's running a tad under 60.  I've rechecked and adjusted the throttle bodies thrice; no help.  Does anybody have any knowledge about Michelin Pilot 4s having more grab?  Can anybody describe how much drag the wheels should have?  In other words, I'm not sure if they're dragging when just giving them a spin while the bike is on the jack stands.  Any thoughts about the plugs?  They went in very smoothly.  No hitches at all.  The bike runs great:  No popping, missing, etc.  There is a slight hesitation when starting out that didn't used to be there.  Throttle body adjusting is supposed to remove it, and it's improved over the first time I adjusted it, but there's still a noticeable hesitation when rolling on the throttle off the line.

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norcal616

Winter blend of gas??? Here in Michigan winter blend gas kills mpg...

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2015 fz-07- Hordpower Edition...2015 fj-09- 120whp- Graves Exhaust w/Woolich Race Kit- tuned by 2WDW
 

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rfmueller
2 hours ago, norcal616 said:

Winter blend of gas??? Here in Michigan winter blend gas kills mpg...

I use ethanol free year round.  But, good thought on the topic.

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norcal616

I dunno..I just don't trust the dash board to give me accurate figures... you should only be balancing one throttle body which is the right one, the left one is the reference one... dirty airfilter... maybe the gas station changed it "brand of ethanol"...I dunno what else, but you could be chasing a ghost over a stupid computer algorithm that slowly adjusts over time...

 


2015 fz-07- Hordpower Edition...2015 fj-09- 120whp- Graves Exhaust w/Woolich Race Kit- tuned by 2WDW
 

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rfmueller
34 minutes ago, norcal616 said:

I dunno..I just don't trust the dash board to give me accurate figures... you should only be balancing one throttle body which is the right one, the left one is the reference one... dirty airfilter... maybe the gas station changed it "brand of ethanol"...I dunno what else, but you could be chasing a ghost over a stupid computer algorithm that slowly adjusts over time...

 

I measure actual consumption/miles over 3 to 5 tanks cumulative.  The computer always reads 5 - 8 mpg lower than the real mpg, so as long as things are running fine, I don't bother calculating anything, but now it's all done by hand.  Dirty air filter could be it.  I live in Salt Lake and it's pretty dusty around here.  I'm also sort of fishing for people that may have noticed a difference when they went to the Michelin Pilot 4s.  

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bugsinteeth

it's probably nuthin more than the temp change from summer....I would be checking the pressure in your tires

and making sure that they are right up to pressure or even a pound or two above max.....

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RobZilla

Going from worn stock tires to new tires with a different profile could have increased the diameter of wheel and effect the mileage. 

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Bountiful
5 hours ago, RobZilla said:

Going from worn stock tires to new tires with a different profile could have increased the diameter of wheel and effect the mileage. 

I was thinking something similar but didn't want to commit to saying anything, it's a subtle change, but depending on how worn they were, I suppose this is technically the way physics would technically affect that change... weather it's significant enough to be the cause or not, who knows?

Edited by Bountiful

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sorkyah
On 11/26/2019 at 9:45 PM, rfmueller said:

Dirty air filter could be it.  I live in Salt Lake and it's pretty dusty around here.  I'm also sort of fishing for people that may have noticed a difference when they went to the Michelin Pilot 4s.  

Might be a combination of the two, but as far as the tires go, only the sidewalls are grippier 

Pr4s have a harder compound than the 3s down the middle, and a softer one on the shoulders as part of michelin's 2CT design

 

I would check the air filter, also, make sure your tires aren't underinflated

The pilot road series likes a bit more pressure than what the manual tells you I run mine at 35/38 and get a drop of 3-4 mpg when the pressure is set at oem of 34/34

 

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ATGATT... ATTATT, two acronyms I live by.
 

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rfmueller

Hmmm.  Interesting tip.  I'll check in to it.  Thanks!

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YZEtc

Yup, if you haven't done it in a year or more, I'd replace the air filter. I always used the OEM Yamaha air filter.

It may or may not be the reason for your MGP change, but it is important to do once a year, in my opinion.

In cold weather, I have noticed a slight decrease in MPG with ALL of my street-going vehicles over the decades, even my Ford Ranger.

By the way, I'm amazed somebody can get 60 MPG at all.

I would average 45 - 48 MPG on my FZ-07.

Edited by YZEtc

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shinyribs

Like Norcal616 said, my first thought was winter blend fuel as well. Easily worth a 5-10% drop in fuel mileage for me. 

Strictly personal opinion, but I have no idea why Yamaha asks to run such low tire pressures on these bikes. I suspect they do it for comfort reasons (we don't have the most bestest suspension),  but the 32 or 34 psi recommended feels like riding on flat tire to me. Running my typical 38/42 psi not only gives me better fuel economy, but the handling is just so much crisper. $0.02

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geophb
27 minutes ago, shinyribs said:

Like Norcal616 said, my first thought was winter blend fuel as well. Easily worth a 5-10% drop in fuel mileage for me. 

Strictly personal opinion, but I have no idea why Yamaha asks to run such low tire pressures on these bikes. I suspect they do it for comfort reasons (we don't have the most bestest suspension),  but the 32 or 34 psi recommended feels like riding on flat tire to me. Running my typical 38/42 psi not only gives me better fuel economy, but the handling is just so much crisper. $0.02

Im the complete opposite, anything over 30psi feels like im on steel wagon wheels! Ive been running 30 front and back, seems to work fine. 👍

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DewMan
1 hour ago, shinyribs said:

Strictly personal opinion, but I have no idea why Yamaha asks to run such low tire pressures on these bikes. I suspect they do it for comfort reasons (we don't have the most bestest suspension),  but the 32 or 34 psi recommended feels like riding on flat tire to me. Running my typical 38/42 psi not only gives me better fuel economy, but the handling is just so much crisper. $0.02

On my 2017 US model the owners manual it recommends  33psi front and 36psi rear. I've found it to be acceptable for my riding.


DewMan
 
Just shut up and ride.

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Grant31781

Check your odometer against a gps app. I used digihud. Ride the bike 50 or so miles and compare your bike odometer to your gps one. Most vehicles I have checked read 4% higher than actual(GPS). Some read spot on. 

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rfmueller
13 hours ago, YZEtc said:

Yup, if you haven't done it in a year or more, I'd replace the air filter. I always used the OEM Yamaha air filter.

It may or may not be the reason for your MGP change, but it is important to do once a year, in my opinion.

In cold weather, I have noticed a slight decrease in MPG with ALL of my street-going vehicles over the decades, even my Ford Ranger.

By the way, I'm amazed somebody can get 60 MPG at all.

I would average 45 - 48 MPG on my FZ-07.

The OEM says to change the filter every 24kmi.  Here in Salt Lake, that may be a bit much since it's desert.  Right now there's about 16kmi on that filter.  I have a new OEM filter on the shelf.  I'm also waiting for Iridium plugs to arrive.  They keep delaying shipment.  

In prior years, the cold hasn't effected MPG.  It did on my old Vulcan, but the last two years I've owned the FZ, it's stayed pretty tight with 65 - 66mpg.  It's important to me given the amount of riding I do:  Usually about 7kmi/yr.  Some areas across Nevada don't have many gas stations (like for 160miles) so I carry an extra gallon, but with lower MPG, that same trip would be a bit too close for comfort.

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rfmueller
5 hours ago, Grant31781 said:

Check your odometer against a gps app. I used digihud. Ride the bike 50 or so miles and compare your bike odometer to your gps one. Most vehicles I have checked read 4% higher than actual(GPS). Some read spot on. 

That's a heck of a good idea!

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rfmueller
9 hours ago, shinyribs said:

Like Norcal616 said, my first thought was winter blend fuel as well. Easily worth a 5-10% drop in fuel mileage for me. 

Strictly personal opinion, but I have no idea why Yamaha asks to run such low tire pressures on these bikes. I suspect they do it for comfort reasons (we don't have the most bestest suspension),  but the 32 or 34 psi recommended feels like riding on flat tire to me. Running my typical 38/42 psi not only gives me better fuel economy, but the handling is just so much crisper. $0.02

Since you've specified the pressure you're riding at, and not having braking issues do to the loss of friction area on the tire to the ground, I'll give those pressures a shot.

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shinyribs
2 hours ago, rfmueller said:

Since you've specified the pressure you're riding at, and not having braking issues do to the loss of friction area on the tire to the ground, I'll give those pressures a shot.

But,of course, keep in mind that I am a random idiot from the internet, so your safety choices should definitely not hinge on my opinions!

38 rear and 42 front are just something I came up with through the years that give me good results in general, but there are exceptions that you have to use your own common sense on. For example, Shinko 009 rear tires are slow to warm up and of a pretty durable compound. The carcass is also very rigid. So, in the case of those specific rear tires, I ran them at about 34 or 36 psi to get them to squirm around and warm up quickly. Granted, I was riding them harder than they were designed for, so forcing them to get warm and "sticky" was just a compromise I was playing with. On the flip side, Conti Motions are extremely thin-walled and flexible. I could detect a loss of a few psi very easily with those tires. 

So...yeah, just approach it with open eyes and some caution. 

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