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Touring odyssey Overdrive mpg

8K views 6 replies 6 participants last post by  cyrus813 
#1 ·
Bought an used 2007 odyssey touring a month ago and been crying over spilled milk since.

You guys on the forum have been great and have gained a lot surfing through. So putting in my cents :smile:

Terrible mileage, same as my 4.7 V8.
Oil change done at dealer in May. I changed out the air filter after I bought for the heck of it.
Tire pressure 38psi.
Looked at the MAF as an internal indicator and its pristine, still sprayed some MAF cleaner and put it back.
Two tanks with techron injector cleaner.

Hwy or city its 15 to 16mpg on the multi readout.

Been calling dealer and been hearing "its normal".

Recently I noticed something and verified it last night with a long drive.

I count the shifts and the instant mpg readout gives 25 to even 30 on 4th cruising 45 to 50 with ECO on. I feel the shift to 5th (OD) and the ECO still on the mpg drops to 12 with no change in gas pedal or speed or gradient.:confused:

to check I flipped D3 on (cancel OD) still level road and as I would expect the engine rev'ed then I swithched of D3 mpg back to 25 before OD kicked in and then mpg down to 12.

sorry for the writeup and thanks for reading.
Has anyone else seen/diag'ed this.
 
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#2 ·
Just saw your post. 065 My EXL with same engine - we get about 18-19 in town and just did a summer trip with 4 and bikes/camping gear/luggage - pretty full, 23mpg avg. Some folks get higher but speed limits high around here and we use AC a lot, including a little bit of idling w/ac on, something I try to avoid but when you have 3 people waiting for you to take a leak get coffee and its 99 outside...you bite the bullet.

Surprised your VCM appears to be causing less MPG...Shooting from the hip, maybe you can figure out how to turn it off and try that for a while?
 
#3 ·
Rule #1 for the OP. Do not trust the toy of the mpg thingy on the Touring. Count mpg the old fashioned way and report back.
 
#6 ·
It is pretty straight forward to calculate MPG. When the manual calculation matches the car's numbers to the tenth of the MPG, I think one can pretty safely assume the "MPG Thing" is working properly. If you're serious about calculating MPG, I suggest you check your trip computer several times to see if it is consistently accurate. I check every tank of gas against the trip meter in all my cars. Keep in mind that if you don't always get your tank completely full, only a long-term average is going to get you a particularly accurate answer. If it works correctly, the built-in calculation is right all the time. The built-in calculations can also help you learn your most efficient speed for a given setup. For example, I get about 27.1 or 27.2 MPG in the 65-70 MPH range. As I approach 75 to 80 MPH, the MPG drops down to about 26.

Now if you REALLY want to get serious, you need to compare your speedometer / odometer to a known accurate reference like a portable GPS that calculates based on satellite position (and reports the MPG or miles traveled directly), because not only are many cars' odometers not completely accurate, but tires sizes vary from set to set (even with the same nominal size). In fact, I wonder what built in GPS systems do as far as reporting speed on cars. This Honda is my first car with a built in GPS, though I have owned and used at least 6 portable units. As far as I can tell, there's no place this car reports the satellite-based speed, but it has to calculate that info and I doubt it overrides a mechanical speedo that would have to be built in for the odometer.

Tire diameters also change (all of them) over the life of a set of tires as the tread wears off them. They can actually vary by several percent over the life of a set of tires on some cars. Just about all the computer or a person can do without something like a GPS based number for speedometer / odometer accuracy is assume the speedometer is correct all the time.

If you've never compared your speedo to a GPS, you may be surprised what you find, BTW. I've sometimes found as much as a 10 percent discrepancy between the two.

That's the way all of this strikes me.

As "they" say, YOUR mileage may vary...
 
#7 ·
Sounds like the stator clutch is bad in your torque converter when that happens you lose efficiency as the input and output speeds of the converter get closer to each other and when it trys to lock up it will it will kill efficiency and mpg
 
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