Did reprogram affect your mileage?

My mpg was reduced a bit after the campaign. maybe not so bad now, i am able to avge. 50 plus on the hwy, but i have to drive slower, 64 or 63 mph.

 

I have noticed no change since the reprogramming. I understand the reason for the reprogramming was that with some '04's the ICE would shutdown and not restart as it should have. I had this happen once. (It finally restarted after a several minute wait with the car powered off.)

If the mpg drops after servicing, I would suspect an oil over-fill problem.

Also, after a tire rotation, you may find that the tire pressure is not what you usually maintain.

I agree that a large (10-20mpg) drop after the reprogram suggest a malfunction. I'd insist on another reprogram.

 

i hope it doesn't do what lexus put into their programing.. with the 400h, you get three tries for the ICE to fire.. if it doesn't fire, then it locks out.. and you have to take it to a dealer.. so i plan on testing this with our 400h?.. no..

 

Already posted here my results. Get way better mpg with the reprogrammed computers.
Very glad I got it done and early.

 

I believe that my dealer performed this upgrade on my car during my 5K oil change/service. I also saw a change in mileage but only on the MFD. By this I mean, my MFD mileage dropped by several miles per gallon, but my calculated mileage based on miles driven divided by gallons pumped stayed approximately the same as before. I have not noticed any difference in when glide can or cannot happen. Driving behavior seems about the same. In the end, this has been a good thing because my MFD mileage was consistently 2-4 mpg too high, and the update brought it closer to my calculated mileage.

One item of note: When the dealer did my service, they identified that my tires were set at 38/40 (or whatever the hell I had them at) and reset the pressures to Toyota specified numbers. This temporarily drove me batty until some kind soul here suggested checking them, and I was able to bump them back to 40/42. Perhaps part of the problem some folks are having might be related to lower tire pressure?

 

I had mine done early January. I can't make any claims to mileage difference as we have had fall, winter, fall, winter, spring, winter since November. My last few tanks have been about 45 MPG. Higher than last winter when the car had < 5K miles on it. I had numbers in the high 30s and low 40s execpt when it was below 10F for HIGHS for 2 weeks. That tank was just over 32.
However we are NOW having the kind of temps we should have had the end of Jan and early Feb. Though I only have about 100 miles on the tank, I watched it drop from 45+ to just barely over 40 the last couple of days.
In general I seem to be experiencing similar behavior to last year, when it is cold (under 32) the car is much less likely to go into electric. When even colder (< 15), it is not willing to go into forced electric even though it has been running for some time and the graph shows 7 green bars. And it has that nasty habit of running while stopped early in my morning commute, without the heat on and showing full blue bars so it doesn't even charge the battery. I HATE when it does that!

It does seem to hit 1 block on the gas guage earlier than I expect and I can't cram in extra so I don't know if there is a change with that or it is just the colder temps affecting the gas tank bladder. The pumped gallons MPG calc is still 1-2% lower than the computer calc, as it has always been.

If you are truely seeing a 20 MPG difference on a full tank between the computer calc and real miles/gallon, there is a problem not related to the 50P service.

As far as the reprogramming, they can't just 'give you back' your old one. It isn't like there is a CD they toss in somewhere. Does the code exist somewhere? Probably, but Toyota isn't going to have people bouncing around with all sorts of back level code.

For those interested in oil overfills: After the 1/8" over fill at 5K miles and 1/4" (a full 8 oz, I took it out) at 10K, I gave them 4 quarts of Mobil1 at 15K and said I wanted 1/2 bottle back. I put in about half the remaining pint the next day to get to the top mark. I'm guessing they are either/and/or

• not so good at draining ALL the old oil
• not so good at making sure they put in ONLY 3.9 quarts.

 

I have not done the 50P yet. I postponed doing it last year because of This Post and have not been to the dealership this year. I wonder if these software version issues could be contributing to the differences people are seeing. Anyway, since you can't get the old software back, it might be worth trying to get a re-flash with the current software. Always a hard decision since I guess it could always get worse.

 

Much of the observed changes in ICE behavior following reprogramming probably have nothing to do with the reprogramming itself.

Part of the reprogramming process removes the "tailoring" of engine parameter controls (timing of ignition and injectors, maybe valves) that the car does continually. In other words, the car "learns" about your driving habits, warmup cycles, and then changes many default values for the equations that control the ICE. This way your emissions and mileage and performance can be tuned automatically based on the gas you use, your driving habits, and for those of us who keep cars forever, aging of the engine (reduced compression, etc).

Following any reprogramming, the car must relearn. The old values are erased and changed to factory defaults. It will take several tanks to relearn. Not only that, if it is relearning under different conditions (like weather or gas), it may not return to the same "state of tune" as before for some time.

Even if you reflashed the ECU with the SAME programming, you would see this effect.

Give it a few tanks. Mine has crept back up to 0.5 mpg of the old mileage after three tanks.

For the owner with the MFD misbehavior, this is unrelated and is also a documented problem. Search the site for your symptons (loss of radio control, maybe A/C control, blank or frozen screen), and you will find info that will help you convince the dealer to replace your MFD.

 

I had the most recent reprogamming done about 4 months ago. After that I took a 2000 mile road trip. I found that for the first 1000 miles, the system did behave diferently and the mileage did go down a bit. (Remember this is in the middle of winter when everybodies mileage goes down because of weather and reformulated gas.

Then at about 1000 miles, everything seemed to ga back to normal. And this week when the weather finally hit the 60s and 70s I had the best mileage ever, with an average of about 56 for mostly highway driving.

 

I had my 15,000 mile service done in January (per my specific instructions - used my oil {3½ qts Mobil-1 5W30} my tire pressures {40/38}, SSC-50P and brakelight switch replacement, and tire rotation).

It's hard to say about any change in MPGs. While they appear about 8-10% lower, rotating the tires could affect MPG until they settle-in, and our North Texas weather is in its "different every day or two" mode, say from 28º one day to +55º couple of days later.

Still, at ~5.12¢/mile for fuel, it's GREAT!