trans improvement and mileage

[JimKellyfan]

:headbang:I noticed before, my mileage average for my driving style, I get 28 mpg city and 38 mpg highway. I am a spirited driver. I just wanted to share, I have flushed my transmission (around 71k miles), first time per records (I bought the car at 68k). While driving before the flush, I thought it shifted just fine. I didn't like the way the fluid looked, it looked about mid quality, and thought a flush would do it good. I underestimated. I notice now, it shifts seamlessly. I can almost guarantee I get better mileage, and will report back my averages. I typically do not go far (it may take a month), but will report back the mileage gains, if any. Based on how much better it shifts (went from good to great), I predict I get at least a 1 mpg gain. Just wanted to share so as to help in the quest of great mileage. Me, coming off a 94 Caprice wagon (15 city/23 highway which is fantastic for that big of a car, by the way), I am still in the ecstatic with what I have phase, knowing some of you are getting 50 mpg. I flushed with a graduated bucket, and stock WS fluid, 8 quarts, then a half a quart to top off from spillage.

[junorico24]

Can you do a DIY on how to flush the tranny? i thought i would ask because I have no shame..:laugh:

[HANZO_187]

I second that. I'm considering flushing the fluids out.

[jack black]

I can almost guarantee I get better mileage, and will report back my averages.

Looking forward to the report. From my experience, oil changes has zero impact on fuel efficiency, unless one uses wrong viscosity before or after.

[junorico24]

I second that. I'm considering flushing the fluids out.

I've done the gear box drain and fill on my 2007 manual hatch but never a flush.

[evo165]

Looking forward to the report. From my experience, oil changes has zero impact on fuel efficiency, unless one uses wrong viscosity before or after.

I am sorry that i don't quite agree with your above statement. Transmission oil is there to lubricate our manual gearbox and auto gear box use them to lubricate and provide high pressure to make the solenoid works to make auto gear shifts.

As oil age due to heat and constantly moving... the oil will lose it properties and get thicken up over time... Maybe 80k and above... Once the oil properties is weaken and viscosity get slightly thicker, your car mile per gallon will be affect.

The principle is the same like a engine oil. People to tend to feel "lighter" and get better mileage after engine oil change. Just that our gearbox oil last longer than our engine oil.

P.S. If we constantly change the gear oil within the service period, we may not be able to feel the different. But if owner doesn't follow the service period, say 100k over mile. Changing the gear oil will make you feel the different. The effect is more drastic for Auto gearbox than Stick gearbox. :thumbsup:

[JimKellyfan]

I did post in another spot, the DIY here:
http://www.yarisworld.com/forums/showthread.php?t=25393&page=4
I can further iterate if need be, let me know. (the diy part)
My mileage thoughts are simply this. I noticed it shifted fine before. Then, it seemed to be seemless or more seemless afterwards.
My thoughts there, Toyota, like many other car makers, moved away from the 2 speed and 3 speed trannys. They did so for trannny life, but also a ton of efficiency was found for many reasons. One is lower rpm rises to get to highway speed or speed (fuel mileage gains). Another is for durability.
Anyway, I would imagine, if the shift is going smoother, happening quicker and more seamlessly, one would get better mileage, and of course prolong the tranny life.
Another good reason to flush (not manuals / automatics) (drain and fill manuals, no better mileage there, just longer gear/trans life). Anyway, trans fluid in the autos, especially the WS fluid is very Hygroscopic (water absorber). So, even if low miles, over time, will be a different viscosity and nasty. My wife's 07 Camry XLE, we bought it with 27k last year, V6 auto. I did a drain and fill on it when we got it and that fluid was gross (time and hygroscopic properties did that). I will flush it by 50k.
So, like I said, not sure on the mileage gain, but, based on how mine shifted before and after, I think I might get something out of it.
Hope so, just wanted to share what I found mainly with shift quality.
:headbang:

[JimKellyfan]

1st tankful, 30.15 mpg, that beats my city average of 28 mpg. I don't plan on a highway venture until I can drive up to PA without any snow or ice, so maybe next month, maybe not. But I will report mileage as I fill up what my mileage was. I am psyched, it may be a good thing for mileage, besides the real reason of trans longevity.

[JimKellyfan]

I had a change in plans, and ended up going from Charlotte area to Burnside, KY last weekend. Driving route 85 to 40, through the mountains and up 75, through more mountains (not like Rockies, but steep enough / 20 miles @ grades), anyway, a decent test. The mileage I got 39.80 and 39.84.
So, given both city and highway testing post flush at 70k miles (first time) has brought me an overall 1.8 mpg gain. Not bad. I just wanted to share.
Makes me want to do the wife's Camry sooner. (drain and fill done when bought, 30k-ish) Probably do hers between 40-50k, realistically. Mine, next flush on trans will be 30-35k, pending how the fluid looks and mileage is. I like to be proactive and am kinda like Tim Allen, over-do-er. I would say flushing at 30 - 60k, would be good, depending on use. I haul weight at times, and am spirited in between Home Depot / Lowe's trips. So, for me, closer to 30k is better. I like to go by color of fluid and feel of trans and habits (use).
Hope this helps someone. Done reporting mileage and satisfied with results on my automatic. Manual would not get these results, but manual drivers have the mileage edge, if shifted per OM.

[UberSilver]

Fluid flush will not get you 50 MPG. I can't believe anyone is getting anywhere near 50mpg from a 1.5L engine. My best on a flat trip of 400 miles was 43 mpg, but I never broke 60 mph for the whole trip. And I flushed my trans last year.

[roxy1]

Fluid flush will not get you 50 MPG. I can't believe anyone is getting anywhere near 50mpg from a 1.5L engine. My best on a flat trip of 400 miles was 43 mpg, but I never broke 60 mph for the whole trip. And I flushed my trans last year.

I don't know about 50, but my lifetime average on my manual 2013 is 43.4....not too hilly, mostly 45-60 mph light suburban and rural commuting, 10% city (true city, sitting at lights, not moving for minutes at a time).

[nookandcrannycar]

Fluid flush will not get you 50 MPG. I can't believe anyone is getting anywhere near 50mpg from a 1.5L engine. My best on a flat trip of 400 miles was 43 mpg, but I never broke 60 mph for the whole trip. And I flushed my trans last year.

I've had many tanks over 43 MPG, also probably never breaking 60 MPH and going 55 MPH much of the time.

[JimKellyfan]

I got 44 mpg, and half an hour was stuck in Charlotte traffic. That was on super gas. Not worth the effort, especially if it doesn't ping on regular gas. Typically get 29.5/39.5 depending on vehicle load (goin to beach with it jam packed netted me 33 mpg average. So, weight loss is at a prime for the hyper milers, FYI....

[Ben_]

Oil that has lost its lubricating qualities and it's viscosity will cause drag on the drive line decreasing fuel economy. Synthetic lubricants should also have better qualities and increase fuel mileage

[JimKellyfan]

Oil that has lost its lubricating qualities and it's viscosity will cause drag on the drive line decreasing fuel economy. Synthetic lubricants should also have better qualities and increase fuel mileage
Agreed.
But, for me, I will just use what it calls for.