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Discussion Starter #1
Well that probably got your attention, but it's true. Here is the whole story behind my car, my driving style, and the trip.

First the car: I just bought it about a week ago. It is the I2 EX (no navigation). This car was a dealer demo car so they have had it for 11 months and it had 610 miles on it. I put about 100 miles on it running around town before this trip. On my trip from Pocatello to Coeur D'alene the tire pressure was 33psi in all 4, I moved it up to 38psi while I was there.

My driving style is "normal". Not Hypermilage style, and not race car (I have an S2000 for that) style, but pretty much with the flow of the other two cars at the stop light. I usually set curse at 78mph and just let it sit there on the freeway. Around town, I am pretty close to the speed limit as racing around town doesn't actually save any time, towns not big enough for that.

The trip: I live here in Pocatello Idaho, which is in the South East region of the state and sits about 4800 foot of elevation. I drove to Coeur D'alene (CDA) Idaho which is about 530 miles from here. To get there I drive I-15 North to Butte MT(250 miles), Turn left on I-90 and continue to CDA(280 miles). I think Butte sits somewhere around 5000 foot, and CDA is something like 2020. There highest pass is between 6000 feet and 7000 feet. The first leg of my trip was Pocatello to Butte. This is where the trip meter said 34.5mpg and when I filled it, I calculated it at 31.175mpg. This was rather low I though. I know the owners manual mentions that the break-in period is something like 600 miles, but I am figuring the first almost year, only 610 miles were put on this car, so if anything I could see the fuel gumming up the spark plugs etc, not actually breaking in the car. I bet it never even got fully warmed up! Anyway. The second leg of the trip was from Butte to CDA, greatly down hill with only a couple passes in it. This resulted in 37.1mpg calculated. While I was in CDA I did a trip to Spokane WA in the evening with the weather about freezing give or take a few degrees. This resulted in the best fuel economy yet at 41mpg calculated, but was slow at 60 to 65 with enough traffic that the air flow was broken up. The drive home from CDA back to Butte it got about 38mpg with cruse at 76mph, and the calculated was spot on with the trip meter. Then the last leg from Butte to Pocatello I again had the cruse set at 76, but there was a horrendous head wind all the way back. This leg resulted in the trip meter of 36.1mpg. I haven't filled the tank yet so I haven't calculated it, but I have hopes that is accurate.

Does anybody have record of there driving style Vs. millage Vs. miles on the car? Does this look like the normal break in progression? Also, is there any kind of firmware update as this car is about a year old in reality.

Another thing I noticed was this whole trip I had the ECON on. The first 100 miles or more are at a constant slow uphill slope. With the cruse set at 78 it would vary 78 to 74mph. Also the assist would turn on for 30 second to a minute, then it would shift to charge. This would move back and forth constantly for the same speed even. I have no idea what kind of algrythm this car has, but if everything is constant like that, I would think it would just sit at a throttle level and not be messing with discharge and charge on the assist. Any ideas with that?

I have spent a couple days reading other posts, I think 31mpg is way below everything. I also see 50, 60mpg posted a lot. How fast are people driving to get this? Cruse at 35mph? Do you have to live at sea level in Florida to get this?

Thank you.
 

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Discussion Starter #2
I should also add that I read a thread about break in where it looks like people are seeing key points at say 1k, 3k, and 5k miles. But has anybody started out at this low of millage? I think I am now at 1850mi on mine.
 

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Your speed is probably the main thing that is reducing your mileage. No one is getting near 50 MPG at 78 mph. The EPA highway number of 43 is for slower speeds in warmer temperatures. The hybrid technology is not helping on the highway, only the low drag coefficient and small, efficient engine. The annoying charge/discharge cycle on long uphills is only lessening your mileage by incurring the road trip losses of charging/discharging the battery. I too am surprised that it does this behavior. After break in, you may get few more MPG, but I think you will be lucky to achieve even 40 MPG at 78mph in hilly terrain in the winter.

I have noticed the gas quality matters, I used to think all gas was the same, but Shell (so called Tier 1 gas) seems to do a lot better than Hess. I get from 43 to 48 actual on the highway, but I travel around 60 MPH to acheive this, and highways here are relatively flat.
 

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Your speed is probably the main thing that is reducing your mileage. No one is getting near 50 MPG at 78 mph.
I agree, though the combination of high altitude (thinner air), cool temps, and low miles on the car may be contributing also.

In January, I got about 45 mpg (real mpg, about 47 on MID) round trip Boston-NY running mostly in the 60-70 mph range on mostly rolling hills terrain, with a little bit of city driving on each end of the trip. My I2 had about 4K miles when I made that trip.
 

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I just bought mine about a month ago here in Texas. It has about 200 miles on it and i get between 30-33MPG with econ mode on. Its prettty flat out here but its been anywhere 30-50 degrees. I hope that when the temp gets a little warmer and i put some more miles on it it improves. None the less i frickin love it!
 

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Discussion Starter #6
I have no delusion of getting 50 mpg at 78 at this elevation. I do however have hopes. I know the drag force is a square of the speed relationship. I am surprised that cool weather actually decreases economy though. It should increase O2 density for more efficient burning and greater delta in temperature resulting in more expansion in the cylinder ultimately resulting in more power. With a drag coefficient less then one I would think this would out weigh the increased frictional/drag on the car. This is obviously not the case with everybody's input. I know in Washington state they would use Ethanal blend in the winter which has less energy per gallon (volume) of fuel. Is this the true cause of less F/E?

Anyway, back to the overall, is it really unreasonable to expect 40mpg at these speeds? There really is a lot of nothing out here. When I travel I usually go 200 to 300 miles before I have to kick cruse off, I would much rather keep my speed up. :)

I also understand that the electric assist does no good at highway speeds, I am counting more on the efficiency of the motor and drag to give me better economy. Right now the 2004 Toyota Tracell is getting 35mpg in the same trip/conditions. I would hope this would have an edge on that!

I was happy this evening it looks like my running around town is coming in about 48mpg (per computer) which is 10mpg better then it did before this last weekends trip, so there is some great improvement there.
 

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Discussion Starter #7
I do think the car is great. This last weekend I put my skis/gear, mtn bike, disk golf gear, racquetball gear, sleeping bag, cloths etc all in this car and didn't block any of the view out the rear window. I did have to move the passanger seat all the way up for the skis to sit flat and be straight from the back of the car forward, but I travel alone so it doesn't matter at all, take the head rest off and it doesn't impede my view either.
 

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Anyway, back to the overall, is it really unreasonable to expect 40mpg at these speeds?
I don't know how much difference the altitude makes, but here in the northeast, near sea level, I would expect around 40 mpg at speeds in the high 70s, and maybe even a little better in the summer, though I haven't traveled that speed for any great distance so don't have any real data.

With regard to mpg decline in the winter - I suspect the winter gas mix for smog control has as much, if not more, impact on mpg than the air temp - though maybe the denser air has a bigger impact on drag than I suspect.
 

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First, I'd say turn ECON off on the highway. You'll probably gain a good 3-4 mpg with it off, and using cruise control. ECON is better suited for in town, and slower driving.

You'll gain another 2mpg or so after 3000 miles, and maybe another 1-2 after 10k.

Then you'll gain a good 5 come summer with the warmer weather.

If you can, slow down, but I know that's big country and would take forever to get anywhere going just 60 mph. However, it's easy to hit 50mpg, cruising, with ECON off, just going 60mph.

But if slowing down isn't worth it to you, don't worry about it.
 

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yeah, im not too worried about it. Its the first new car i've had in 10 years so im very happy with the 30-33 im getting. My truck only gets around 13 which is why it sits in the garage all the time :)
 

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Discussion Starter #11
yeah, doing 60mph Vs 78 add just about 2 hours to the drive, kind of tough to swallow. I will try with the econ off during my next trip (could be tonight, not sure if I am going to take the I2 or the truck as there is a nasty pass that should be getting some snow this evening and tomorrow).

I have not read through the addons or modifications section yet, but I live up a hill. Is there any plug in option for topping off the batteries when I get home? I also saw someone has and ODB2 port reader. Does anybody have details on these? I will search through the forum this evening for more details on these things. Maybe HID lights as well. I think COBB has been running the HID lights.
 

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I always make it a habit to switch my MID to display the live MPG reading. I always try my best to keep the bar right around the middle (45-50mpg). Often times when I'm cruising down the highway on a flat surface, that bar will go between 50-60mpg and rest. This can even be achieved driving 65-70mph with ECON ON and A/C OFF. I never use Cruise Control because I drive an LX.

So that is my tip: Always drive with the MID on the "Live" MPG screen!
 

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I did that same jog from Butte to CDA on our trip out west last year. We were going at least 80 MPH with ECON off. I don't remember for sure what the MPG was but it was in the 35ish range. It was 70 degrees then. So throw in colder temperatures and a newer engine (car had 4000 miles or so at the time) and I can see those numbers being realistic.

Just as many have mentioned, the biggest thing eating your MPG is your speed. So its a trade between MPG and time that you have to decide on for yourself. We were in a hurry to get to the hotel in CDA so we weren't going to poke around on that day of our trip, so I had to swallow the crappy MPG.

The good news is that just before that leg when we were in Yellowstone going 35-40 MPH, I was getting 60 MPG.
 

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Discussion Starter #15
Ok, this weekend I did a trip to Salmon, ID from Pocatello. There is only one pass and it's at 7200 feet. I set the cruse on 72 for the first 75 or 80 miles that is on I15, this is on the same leg as my first trip. The computer said 44mpg. Then I took a 2 lane highway the rest of the way to Salmon. I set the cruse at 68 that whole way. When I filled up the computer said 46mpg, the actual calculated was 40mpg. this is getting closer to acceptable. The temp was 32 when I left Poctello, bottomed out at 20 on top of the pass and then went back up to 33 when I got to salmon. It's about 210 miles each way. I haven't fueled up at home yet, but the computer again says 45.9mpg. Same speed and driving conditions on the drive home.

Also, I turned Econ OFF for this trip.
 

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You're still driving too fast

There's no other way around it...SLOW DOWN even more - over 70 is too fast if you expect big mpg numbers...
 

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Slow down. Haha, that's funny. I'm much happier with what it's getting now, I will still be in the mid 70's, but that's how I drive everything. I was just a no impressed with the 31 on my first leg of my first trip with this car. Close to 40 at these speeds is good. If it get's above 40 in the summer, bonus!
 

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The relationship between wind resistance and speed is not linear. You go 40 to 80 mph, you get 4 times the wind resistance vs twice.

I can keep 54mpg going 70mph, anything over70 and you loose the hybrid system and run purely on motor. Sure drafting helps, but you shouldnt tailgate at those speeds.

Driving my x8 90mph, got me 19mpg.
 

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500+ miles on my new ex to date. had it on the interstate at 80 90+mph then stop and go traffic, jack rabbit starts stops etc. mpg. 30.9 with econ on. econ off driving posted, and nice, 41.9 all on Chevron fuel? The best mpg is 43.8
 
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