Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L
 

http://ecomodder.com/forum/attachmen...1&d=1411481277

These brand new Nissan Micras may look identical, and their official fuel economy ratings also say they're almost twins... but in the real world, they're definitely not!

The car on the left has a 4 speed conventional automatic transmission, and the one on the right has a 5-speed DIY gearbox.

Thanks to Cornwall Nissan, last week I got a chance to put the 2 cars through a head-to-head (simultaneous) MPG comparison on a 20 km (12.4 mi) round trip route.

The car's official 5-cycle EPA style ratings:

• Manual city/hwy/comb: 27.4/36/30.6 mpg US = 8.6/6.6/7.7 L/100 km
• Automatic: city/hwy/comb: 26.7/36/30.2 mpg US = 8.8/6.6/7.8 L/100 km

(For those of you south of the 49th who don't get the Micra, the car's drivetrain and platform is the same as the Versa sedan/Note.)

Route: This was a mostly city drive: a mix of urban (~40%, max. speed ~60 km/h = 36 mph) and ex-urban (~50%, max. speed ~80 km/h = 50 mph) roads, with one brief freeway sprint between interchanges (~10%, max. speed 110 km/h = ~68 mph).

Conditions: cool 10C / 50 F, but sunny & dry.

http://ecomodder.com/forum/attachmen...1&d=1411481929

Driving style: There was actually precious little eco-driving in this comparison, because my dad joined the fun and he led the parade in the automatic. Let's just say that he's a typical driver of the "binary pedal" school (either on the gas or on the brakes). Speeds were around 5 to 10 km/h (3-6 mph) over the posted limit.

To make it a valid comparison, I followed in the 5-speed car and made sure to accelerate as quickly as my dad did in the automatic, and brake as late as he did. There was no neutral coasting, no pulse & glide or anything like that. And I stayed back far enough so there was no unfair aero advantage (draft) for the 5-speed car.

The only significant eco-driving technique I used was upshifting to the tallest possible gear after accelerating. Often that meant 5th gear at as low as 50 km/h / 30 mph on a level road. If I needed more power, I downshifted.


Results:

Forget the official ratings! Once again we see how the EPA testing handicaps manual transmission cars due to dictated, non-eco shift points during dyno testing.


http://ecomodder.com/forum/attachmen...1&d=1411481277

Translation:

• 5.1 L/100 km - manual (46 mpg US / 55 mpg Imperial / 19.6 km/L) *
• 6.5 L/100 km - automatic (36 mpg US / 44 mpg Imperial / 15.4 km/L) *

* Note the Micra's onboard display is a bit optimistic. The display in the Micra SR automatic loaner I drove in July read 4.5% higher than actual fuel economy calculated at the pump.


Moral of the story: if you're comparing a manual vs. automatic vehicle based on the EPA ratings, beware of false automatic hope! Even when the numbers are close, a manual is typically capable of better real world economy, and not even using "hard core" techniques. Just upshift early and upshift often. (The extra techniques are gravy.)


A caveat about this test: the conventional torque converter style 4-speed in the Micra is going to fare worse in a comparison against a manual than a CVT or dual clutch auto/robotized manual would. Newer style automatics are definitely closing the gap. But I'd still get the manual, even if the automatic is rated a little higher. (Such as in the case of the Mitsubishi Mirage, where the CVT is rated quite a bit higher, but owners are getting better mileage with the manual in the real world.)


For full details of the Micra showdown: Head to head: 2015 Micra manual vs. automatic MPG/fuel economy comparison - Micra-Forum.com

Crawling on the Interstate coming west to my house, reminded me of why I don't mind the auto, not that I would not prefer the manual but this auto is decent with 4 gears and a lockup converter.

It needs their latest CVT, then it would cut the gap in half maybe more.

regards
mech

While most people insist that low-quality robotic butlers are more efficient than "DIY" (I am not sure everyone will understand that. You made the gearbox yourself?), one friend said they do that so people pay extra for the automatic, thinking that it would pay off at some point.

I hear you. The Micra's automatic is certainly pleasant enough to drive - essentially seamless shifts at low engine load. And it actually has fairly aggressive programming to get into lockup and hold higher gears.

Yep. Ironically, both of the Micra's closest competitors -- Chevy Spark and Mitsu Mirage -- use Nissan-sourced (JATCO) CVT's. And they have much better ratings than the Micra.

However one Micra owner pointed out to me that there's an argument to be made for the old-school 4-speed automatic in terms of total cost of ownership over the long haul: the manual will probably need a pricy clutch replacement in its lifetime, while the CVT needs expensive periodic fluid changes. The 4-speed auto needs neither. YMMV.

There's certainly a lot of profit in the automatics, especially this old-school 4-speed!

The wife's Rogue had a 10 year 120k warrantee on the CVT. The fluid is expensive but it does not hold that much. On my Insight it was around 2 quarts. Cost around $100 fror them to change it.

On Nissans, I think there is a fluid change warning system that tells you when to change it, but I think the 06 Murano went 95k without any indication of fluid degradation.

Depends on how you drive it and if you tow or not. The Murano was rated for 3500 pounds with the CVT. They have done something to increase the spread between lowest and highest gears. It used to be about 650%, now I think over 800% range between lowest and highest and they did mods to reduce losses. Think the newer ones have two ratios instead of one. The newest Rogue is rated at 32 or 33 highway while her 09 was 28 if memory serves me.

regards
mech

Next Generation XTRONIC CVT | Nissan Innovation Labs

They have the Altima running at 1500@60 MPH, with a 38 highway rating same as my old Fiesta, except the Fiesta was about 2200.

Correction, the ratio spread (lowest to highest) is 7.3 not 8 versus the older 6.

regards
mech

I had the chance to compare the new Mitsubishi Mirage's CVT against the manual transmission version over the same route (100% city driving). In that case, the CVT actually has better ratings than the manual for both city & highway.

As you might expect, the difference there was smaller than what we saw with the Nissans, to be sure: 42 mpg US (CVT) vs. 48 mpg (5-spd).

http://ecomodder.com/forum/showthrea...age-27384.html

A 14% improvement for the Mitsu 5-speed vs. 27% with the Nissan manual.

But it also wasn't as good a test: it was me driving the two Mitsus on successive laps, not head-to-head like we did with the Nissans under identical traffic and accel/cruise/decel conditions.

In my entire driving career (99% on manuals since 1973), I've never had to replace a worn out clutch. For me the gear teeth, bearings, or fork wear out well before the clutch lining is gone.

I'm in the same boat. I've only once had to replace a clutch, and it burned out because of a mechanical problem (rust on the clutch arm preventing it from fully engaging). Not because of the nut behind the wheel.

But I'm also going to say you're not probably representative of the average manual transmission driver. Just look at your car! :)

(By the way: I got your e-mail. Will get back to you.)

Real world automatic reliability
 

My own experiences with automatic reliability is much worse than all the infrequent clutch jobs.

Diagnosing etc an automatic can cost more than a clutch job.

I know lots of drivers who go almost the life of the car with one clutch.

There is a thing called confirmation bias. When people want an automatic, they look for these false reasons to support their preference.

I was not aware of the EPA test method with manuals being done in a way that gives worse MPG results to favor automatics. Seems like that should be corrected!

CVTs are cool
 

I just like the way the Prius C 'shifts'.. Smooth... ;)
My 6sp Escape will sometimes coast into a little null in the drivetrain
and jerk forward, when I really just wanted to go forward Smoothly... :p

I just got another recall service done on the Ford.
Of course they had to re-program the AT's computer, again! :eek:

I forgot to add my latest purchase is an Mitsubishi i-MiEV with the best of both transmission worlds, a 1 speed no clutch gearbox that has a user interface like an automatic, but instant power and no kick downs like a manual. It also has pretty strong regenerative braking so I rarely use the brakes.

More fuel for my fire. I want a manual next time!

Though the little 4-speed autotragic in the Echo has given flawless service since I took the car over. It's not the smoothest trans in the world, but nor is it the worst. If I had one wish at all it would be a little quicker to up shift, it does seem to hold gears nicely/avoid downshifting needlessly.

Mileage ratings are nearly useless, IMHO. My wife's Kia brandishes a better highway rating than the Echo, but the Echo will positively blow it away in the real world. This despite the fact that the Kia will up shift much sooner than the Echo will.

My '89 F-250 still has the original clutch disc, pressure plate, and pilot bearing @ 291k miles. I had to replace the release bearing about 10 years ago. YMMV.

L0L, my dad (R.I.P.) was the same way — but in his defence, he was a motorcyclist. Thank you for a well-detailed report. I have always been a ManTranFan for the increased performance/economy and decreased boredom (I don't really enjoy driving, especially in traffic) but my friend's new Mustang with dual-clutch autochanger seems to have narrowed that gap to near-zero.

Interesting they had a 4 speed slush box. I thought all the automatics were cvt at this point?

I was reading the other day that Dodge made a mistake offering a stick in the new dart. To date of the article I read they sold 6 across the country.

The Prius uses an eCVT or a digital one vs the analog ones we are all stuck with.

Yup, all that. Just look in any scrap yard at how many otherwise pristine cars are there because of terminal AT failure. I have a Suzuki Swift with a dead AT at 80,000km. The first fluid change is only due at 160,000. If it were a manual it might have needed a clutch in another 120,000km.

The company says they offer the slushbox because it's cheaper, and this car is all about affordability: the base car starts at $9998 (5-speed), and even with auto & air, it's still supposedly the cheapest out there.

However, I think it may also be a marketing strategy to protect the Versa Note hatch, which does have the CVT. The Note CVT has a better MPG rating than the Micra 4AT, which is an upsell point to move people up from Micra to Note (which is definitely going on - Note sales have increased since the Micra came out, a little bird told me).

Ah, something like how Chevy will sell a cust who cant afford a volt a cruse?

What's the secret for those of you who've had a clutch last over 200k miles? Clutch in when idling?

No. Don't let it slip any more than necessary when taking off from a stop and rev-match on upshifts and downshifts. Control your speed with the throttle; not the clutch. (or the brakes:rolleyes:).

There's no secret, as such. You just kind of pay attention to your driving.

Oh, and no rally starts.

Clutch lining material is similar to brake pad lining material, and just like when using the brakes, you wear off some of the lining each time you slip the clutch. I consider both of these materials to be slow use consumables when operating the car. The secret to long clutch life is to minimize the amount you slip the clutch, the same as you get long brake life by minimizing the amount you use the brakes. When coasting or idling at a stop, I will usually keep the clutch pedal pressed down unless the coast or light is over a minute and then I will release the clutch pedal with the gears in neutral.

Don't hold the clutch in while idling. Shift to neutral and let it out.

The thrust bearing doesn't get regular lubrication, it's lubricated by a couple of teaspoons' worth of grease and that's it. Holding it in subjects it to unnecessary wear.

When engaging, keep slippage to a minimum. To get started, I goose the throttle a tiny bit to speed the engine, then engage as the revs drop back to idle. The extra kinetic energy is enough to get the vehicle moving, and I let the engine and tranny match up without any extra loading beyond that. Then I add gas.

Your mileage may vary. Too small an engine and that method might not work. It sure doesn't with the Honda, yipes.

Learn clutchless shifting!

( Then replace your synchros instead of your clutch disc? :) )

^^Bad Metro! Bad!

Mirage 5-speed drivers are beating the automatic too (CVT)
 

Sorry! :o

Back to the original topic, here's some more grist for the mill:

Of 60 Mitsu Mirage 1.2L owners tracking fuel economy on MirageForum.com, the manual drivers are beating the CVT drivers, despite the CVT's better EPA ratings:

• CVT (27 cars): 42.1 MPG (US) = 5.6 L/100 km
• 5-spd (33 cars): 44.2 MPG (US) = 5.3 L/100 km

Source.

The CVT is EPA rated 40 mpg (US) combined. The 5-speed is rated at 37.

Note: there's one hard core hypermiler/EcoModder member -- 3dplane -- in the 5-speed group skewing the result (he's averaging 63 mpg US), but even when you omit his results, the manuals are still ahead.

Did Baby Prelude (Roheryn) just need synchros? After my third clutch replacement, I started shifting using just the accelerator, not the clutch, until one day I could not shift, and then she was towed because I "abandoned" her.

I really feel like there are not any skills that I can master to 100%. Walking? No, trip for no reason. Breathing? No, sometimes try to inhale or exhale twice in a row. Drinking water? That one can be life-threatening.

I will skip the story, but some things are not worth the time to achieve 100%

I tend to operate the clutch similar to how an auto does. I relie on it slipping for smooth launches, then release and floor the throttle. If I am out at 3 am I just release the clutch at idle and roll off. If I am in rush hour I release at 3 grand and go.

I havent worn out a clutch myself, but many Ive replaced are because of either an engine oil seal leak, tranny seal leak or just because you are inside that part of the vehicle replacing a throwout bearing, flywheel or pressure plate.

Now pressure plates with broken springs and flywheels with chewed up starter gears is another story. :eek:

You don't master clutches 100%. You just minimize the damage you cause them while you're going about your life doing other things. Of course, every shift is one more shift you've made, paid attention to and (maybe) learned from- even if it's just one of your feet that learned something.

:eek: I use 3k launches for Auto-X (Fiat), 2.5K for the Skyline :D You guys must have some seriously fast traffic. Here squealing your tyres is punishable by having your car crushed...

Only clutches I've replaced were both Nissan/Datsun 4x4 truck's cause I was there anyway at or beyond 100k. Took a 90 Sentra to 195k wife did first 100 then sold it, 97 Saturn 150k then sold it, cobalt's at 105k don't see why I'd ever have to with it. Granted we live in middle of nowhere so average trip is way longer than most and barely any city driving. Get it engaged quickly, then floor the throttle, neutral clutch out at stop lights or coasting .

If you feel like lighting them up, get the rubber dirty or wet first.

I was once pulled over after unintentionally squealing my tires. I was trying to take off quickly, though, and once I started, I should have adjusted to compensate.

Also, I really should have realized that I had a police car behind me.

The officer received another call and let me go. Later, I received a speeding ticket, went to traffic school, and learned that I could have been ticketed for "exhibition of speed," which is eight points, enough to suspend your license.

Having that car crushed might have saved me some trouble, but maybe that had not started yet.

Was 16-17, just replaced 300 or 305 v6 in 67? GMC shortbed handme down with a 350 and put 33x12.5 or the rear, just left girl friends house, and decide to enjoy the new power, 2 block later on main street city leo standing in the middle of the road. Bunch of my older brothers classmates were BS's with him and got a good laugh. Didn't do it again, atleast not on main street. No tickets issued atleast.

oldtamiyaphile, its a dog, it just goes. Its hard to squeal tires.

Fat Charlie, yup, thats how an automatic works. Its just clutch plates, bands a fluid couplant. Lots of slippage and slack.

https://www.youtube.com/watch?v=GJ6atGhmVU8 :eek:

I just used a linky to this post to bolster my view that manual > automatic. Thanks for the comparison!

jcp: someone in that thread replied "too bad the comparison wasn't against a state-of-the-art automatic."

I've done that too. The lower rated 5-speed still won out (though not by as much):

Gas mileage/MPG test: 2014 Mirage CVT vs. 5-speed (sub/urban Ottawa route) - MirageForum.com

that other link completely answers my question about CVTs

Twenty seven point seven percent is the same difference in mileage we get in our Mazda Cx-5s. Wife's is six speed planetary auto with lockup and mine is six speed manual. Same tires, chassis, and both are Sports = 2 liter two wheel drive basic models about same weight except I'm twice my wife's weight. I run more air pressure and wheel/upper grill covers and she used to be almost all highway driving.