Transmission/gearing question

[litesong]

Originally Posted by EcoCivic

...Assuming that the torque converter is 90% efficient at full throttle, it could be wasting up to 15 horsepower on a 150 horsepower engine that could be going to the wheels, which certainly would be noticeable....a manual trans is a lot lighter than an auto and likely has less rotational mass since a clutch is probably a lot lighter than a torque converter.

As stated, I can feel the power difference between our automatic & manual Elantras. The auto companies keep saying they are improving automatic transmission efficiency, but they have a ways to go.

[EcoCivic]

Originally Posted by litesong

As stated, I can feel the power difference between our automatic & manual Elantras. The auto companies keep saying they are improving automatic transmission efficiency, but they have a ways to go.

It's also possible that the ECU's are tuned differently. I don't know that much about Hyundai's, but from my understanding, sometimes MT ECU's are tuned differently (usually more aggressively) than the ECU/PCM for the same car with an auto to make it feel more sporty. There have even been cars where the ECU on the automatic version has been detuned to reduce the engine's power output.

[litesong]

Originally Posted by EcoCivic

.....There have even been cars where the ECU on the automatic version has been detuned to reduce the engine's power output.

No statements were made that the 2016 Elantra engine, reduced 2 HP to 145 HP, was specific to the manual or automatic transmission. Nevertheless, our 2016 manual Elantra feels more powerful than our 2013 automatic 147 HP Elantra.... considerably so AND probably for the reasons that EcoCivic has already given, before his last post.

[EcoCivic]

Originally Posted by litesong

No statements were made that the 2016 Elantra engine, reduced 2 HP to 145 HP, was specific to the manual or automatic transmission. Nevertheless, our 2016 manual Elantra feels more powerful than our 2013 automatic 147 HP Elantra.... considerably so AND probably for the reasons that EcoCivic has already given, before his last post.

Does it feel more powerful at full throttle, or just at part throttle? I am not sure if this is the case, but it's possible that there may be other tuning differences that don't affect peak horsepower. For example, from my understanding, the ECU in the 8th gen Civic MT is tuned so it opens the electronically controlled drive by wire throttle a little more for the same distance the pedal is depressed than the AT version does, presumably to prevent stalling and make the car feel more sporty.

While that wouldn't affect peak horsepower or torque since the throttle would be wide open regardless, it affects how responsive the engine feels and part throttle performance since you get more power when pressing the throttle pedal the same amount, similar to the way installing a bigger throttle body improves responsiveness.

[Ecky]

"Area under the curve" can tremendously affect drivability. An engine with a better torque curve can provide more power nearly everywhere but fall a hair short on peak power and torque.

[EcoCivic]

Originally Posted by Ecky

"Area under the curve" can tremendously affect drivability. An engine with a better torque curve can provide more power nearly everywhere but fall a hair short on peak power and torque.

Very true! I plan to eventually replace my 4-1 eBay header with a 4-2-1 header for that reason. A little less peak power, but more power everywhere else.

[litesong]

Originally Posted by EcoCivic

Does it feel more powerful at full throttle, or just at part throttle?

I find the 2016 manual transmission shows greater power at all throttle positions AND all rpm ranges, than the 2013 automatic transmission. Just thought of something else, because of your question. Do both car engines, rev with equal verve, BEFORE the transmissions are engaged? Would you have any interest in such an experiment? I'll have to test both cars to make a comparative determination. If you don't have an interest, I won't conduct the experiment.

[EcoCivic]

Originally Posted by litesong

I find the 2016 manual transmission shows greater power at all throttle positions AND all rpm ranges, than the 2013 automatic transmission. Just thought of something else, because of your question. Do both car engines, rev with equal verve, BEFORE the transmissions are engaged? Would you have any interest in such an experiment? I'll have to test both cars to make a comparative determination. If you don't have an interest, I won't conduct the experiment.

I think that would be a great test! It would show the differences (if any) in the rate the engine revs at, probably mostly due to the weight of the flywheel and clutch compared to the (likely heavier) torque converter. If you want to, another interesting thing to test would be what the difference is with the clutch in or out on the manual trans. Just make sure both engines are fully warmed up before you test this obviously.

[litesong]

Originally Posted by EcoCivic

I think that would be a great test! It would show the differences (if any) in the rate the engine revs at, probably mostly due to the weight of the flywheel and clutch compared to the (likely heavier) torque converter.

The comparative un-engaged rev tests of the 2013 & 2016 Elantras may have to wait a bit.
My wife & I are going to Mt. Rainier & Chinook Pass, leading to Yakima, tomorrow (in the manual Elantra). Been there with the automatic Elantra twice, while efficiently burning 87 octane, 100% ethanol-free gasoline(E0). Tomorrow, we'll be using (not burning efficiently) 87 octane E10. Any performance differences (other than MPG) between E0 & E10, compared to transmission differences, would be minor.

[litesong]

Originally Posted by litesong

My wife & I are going to Mt. Rainier & Chinook Pass, leading to Yakima, tomorrow (in the manual Elantra). Been there with the automatic Elantra twice, while efficiently burning 87 octane, 100% ethanol-free gasoline(E0). Tomorrow, we'll be using (not burning efficiently) 87 octane E10. Any performance differences (other than MPG) between E0 & E10, compared to transmission differences, would be minor.

We got back from our small trip to Mt. Rainier, 4600 foot Cayuse Pass, 5500 foot Chinook Pass, down to Yakima & up to 3000 foot Snoqualmie Pass. The 2016 manual 145HP Elantra was superior to the 147 HP automatic Elantra, on the steep mountain slopes. Even with the use of E10 (which is inferior to E0), & the slight HP decrease, the manual always had more capability on all slopes, elevations, ascensions, & descents than the automatic Elantra. Even with low power, the manual Elantra gives pleasure in the mountains, that the automatic Elantra can't assure. I still love the automatic Elantra (even in the mountains), but I know which side of my slice of bread, has the butter..... & apricot jam.
The trip computer indicated that the manual Elantra got 48MPG. Using E10, the trip computer would be about 4MPG too optimistic. So a reasoned guess is the trip in the mountains gave 44MPG.