A727 vs A833 vs TKO600 - MPG

[shone190]

Hi guys,


I was wondering, is there any MPG difference between these three transmissions in everyday city driving, in the same car off course?

 

[GetX'd]

A 727 Torqueflite was one of the best transmissions made. They're a Mopar mainstay. I'm not answering your question because I don't know the answer. I just know you can't go wrong with the 727.

i also wanted to reply to someone in Serbia. God bless Mopar Nation - We're worldwide.

How do you get parts way over there? Must be a Huge challenge.

 

[shone190]

Hehe, some parts are coming in ship containers my friend organize every few months, and some smaller parts I buy "regularly" and received by USPS. This is more expensive than in USA, but this is not the same to drive this car in Europe and in USA, you can't imagine people faces when they see the car

 

[GetX'd]

I imagine you blow some minds over there in the land of mini vehicles. Must be cool to strut down the road when they see a big bad Charger strolling by. On ther other hand can't be much to go up against over there. Very interesting. Good luck with all you come across. Mopars forever :naka:

 

[sleepar]

The standard will get the best mpg the auto robs power to operate. I too would go with the 727 with the up grades in it.. a tight auto is close to a standard....

 

[benno440]

6 speed will get the best mpg, due to the longer 2 gears which will lower rpm at cruising speed

 

[shone190]

TKO 600 is 5 speed transmission and I asked for MPG in the city, not highway driving

 

[AMX364]

MPG in city is different then highway. Most difference will be in driving style and not so much as transmissions. What is your city MPG now?

 

[benno440]

well in that case, why not give us the gear ratios of all 3 gearboxes then we can tell you what will be better mpg, or you can work it out yourself, the lower the gear, the lower the rpm, in turn will be better mpg. am i right

 

[shone190]

Forget city MPG and lets include a little math in calculations


On highway with my 3.23 differential, 26.7 wheel diameter and A727, at 2000rpm speed will be 49 MPH, probably a 45MPH because of slippage (non lockup A727) which is not included in calculator. With the same setup and RPM, but with TKO600 (0.64 OD) instead of A727, speed will be 77MPH.


So, let's say that fuel consumption with A727 is 14MPG at 45MPH. At the same rpm with TKO600 speed will be 71% faster. Per time unit, both cars consume the same amount of fuel, because of the same RPM. For the same distance, lets say 60 miles, A727 will need "to work" 80 minutes and TKO600 will need 46 minutes, that's 57% A727 working time, and 43% less fuel consumption
For 60 miles, A727 will need about 16.8 liters (4.43 gallons) and TKO will need 9.7 liters (2.56 gallons).


So 14MPG with A727 will be 24MPG with TKO600 at 2000 rpm constant speed


Maybe there is some "space" for corrections because of larger wind resistance at higher speed, but lets say that fuel consumption will be around 50% lower.


Simple math, right?

 

[coloradodave]

Wrong. It depends on where the motor makes it's torque. If you could get a 50% reduction in fuel just by going to an overdrive, we all would have one. There are too many variables to give an accurate or even estimate a difference in mileage, including what your right foot is doing. Is mileage your top priority?

 

[shone190]

There is nothing wrong with calculation. It is simple math and that has nothing with engine torque when we compare two identical setups with only differences in transmission. RPM where MPG will be optimal is another story, this is just comparison between two identical setups where only difference is transmission. So, whichever RPM you choose, "difference" will be about 50% on highway in the latest gear. Off course that MPG won't be the same if you are cruising at 2000rpm or 4000rpm

- - - Updated - - -

If we use Gear vendors unit with 0.78 OD, there will be about 22% smaller fuel consumption on the highway, no matter what RPM we use for comparison. So, if you have 14MPG with A727 at 2000rpm, you will have about 18MPG with GV+A727 at 2000rpm, simple math

 

[Ron Ward]

Have you ever installed a Tremec into a B-body? Lots of hacking and cutting and moving stuff out of the way.... Unless you are planning on lots of fabrication, the A-833 would be the best choice.

oh.... and install a vacuum gauge. Seriously.... pay attention to the gauge and adjust your driving style so as to maintain as high a vacuum reading as possible and see what your mileage does.

 

[coloradodave]

There is nothing wrong with calculation. It is simple math and that has nothing with engine torque when we compare two identical setups with only differences in transmission. RPM where MPG will be optimal is another story, this is just comparison between two identical setups where only difference is transmission. So, whichever RPM you choose, "difference" will be about 50% on highway in the latest gear. Off course that MPG won't be the same if you are cruising at 2000rpm or 4000rpm

- - - Updated - - -

If we use Gear vendors unit with 0.78 OD, there will be about 28% smaller fuel consumption on the highway, no matter what RPM we use for comparison. So, if you have 14MPG with A727 at 2000rpm, you will have about 19.5MPG with GV+A727 at 2000rpm, simple math

Your missing an important part of the equation. If the load you apply to the motor is above or below the point at which the motor makes its maximum torque, the motor will be working 'harder' and will not give the same mileage difference you are stating. Why do you think manufacturers take so much care in picking the gearing and tire size on new cars? It's to put the motor at its ideal torque point to get maximum efficiency and therefore, the best mileage. If you're not doing this exercise to find out which transmission would get better mileage, as you originally stated, then just what is the point?

 

[HT413]

There is nothing wrong with calculation. It is simple math and that has nothing with engine torque when we compare two identical setups with only differences in transmission. RPM where MPG will be optimal is another story, this is just comparison between two identical setups where only difference is transmission. So, whichever RPM you choose, "difference" will be about 50% on highway in the latest gear. Off course that MPG won't be the same if you are cruising at 2000rpm or 4000rpm

- - - Updated - - -

If we use Gear vendors unit with 0.78 OD, there will be about 22% smaller fuel consumption on the highway, no matter what RPM we use for comparison. So, if you have 14MPG with A727 at 2000rpm, you will have about 18MPG with GV+A727 at 2000rpm, simple math

First off, your 'simple math' is too simple. You've neglected to include wind resistance, so assuming your car will get the same gas mileage at 77 mph vs 45 mph based simply on a gear change is silly.

If in-town fuel economy only depended on gear ratio, forget the TKO and just drive your stroker around town in 3rd gear.

Furthermore, I'm not sure if it is simply cultural differences, but your 'simple math' posts are coming off as smug, and very few of us want to help smug people who are in fact incorrect. I'm willing to chalk it up to simple misunderstanding though.