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Toyota 86 review long term – automatic vs manual – update 8

The automatic Toyota 86 / Subaru BRZ. More than just an easy drive.

THE TOYOTA 86 is mechanically identical to the Subaru BRZ save for one or two tiny details like fine suspension tune, so for dynamics and handling whatever you write about one pretty much applies to the other. I can vouch for this as we’ve got two 86/BRZs in our household, my manual 86 and my partner’s automatic BRZ.

RMP_9962

If I ask nicely I’m occasionally allowed to drive the BRZ, and I have to say… I like it. Yes, even after I wrote this. But hold on, I’m not about to be swapping my own car for an automatic, because I still believe the fundamental principle of true driving pleasure is the mastery of difficult skills, of which a manual gearbox is an important part. Instead, I appreciate the automatic BRZ/86 for its important advantages over the manual.

The first and most obvious is no need to change gears, so it’s an easy drive in stop/start traffic. The second and less obvious is the quicker acceleration off idle for the same revs, which means quieter and less fussy progress. The automatic needs far fewer revs than the manual when driving normally around town, and there is a satisfying urge even down around 2000rpm where the manual is lifeless and sluggish. The paddleshift gearchanges work well too, they feel good and there’s no delay in shifting. The auto loses none of the inherently sharp and fun handling the 86/BRZ is renowned for, but does make it slightly tamer and simpler to drive as it’s easier to feed the power in smoothly. It’s also slightly quieter at cruise speed too, as the revs are a bit lower.

I’d even go so far as to say the auto is more fun around town. But at high speed, high revs…give me my manual any day, even though it’ll be no quicker than the automatic and harder work.

That’s the review bit of this post. Now you are probably dying to know the answer to this question:

Why is the automatic better?

The improved low-speed driving experience in the automatic is due to something called the torque converter.

A manual car joins the engine directly to the wheels, once the clutch is up, so any change in engine speed directly affects the wheel speed. That is why manuals have such wonderful immediacy of response to the throttle.

Automatics, on the other hand, do not usually have a such a direct connection unless they are the likes of the latest DSG systems. Instead, the engine in an automatic car with a torque converter spins a fan (impeller) in what is in effect a jar of oil. That oil then spins too, and there’s another fan inside the jar of oil which is connected to the rest of the drivetrain and the driving wheels, known as the turbine. As the oil spins, the turbine spins too. Between the impeller and turbine is something called the stator which is another kind of rotating fan device.

So with a torque converter there is no direct connection between engine and wheels, and the engine can spin its impeller faster than the turbine. With the help of the stator, this acts as a kind of gearing, so the engine can quickly get to an appropriate rev range and stay there for a while – you can see this in action when you accelerate at medium levels and see the engine revs stay more or less constant as the car gathers speed. In effect, you could say that automatics get extra gear ratios compared to manuals.

At cruise or in other conditions where appropriate torque converters can lock up so there is a direct connection between engine and drive wheels, and it’s at that point the automatic is most efficient. In many cars you can pick this point – select top gear, say 5th or 6th, and accelerate hard from say 80 to 100km/h but don’t floor it. You’ll see the revs rise, the car stay in gear, and after a moment when you get to 100km/h the revs will drop yet the speed remains the same as does the gear. What’s happened there is that the torque converter has helped accelerate the car. You may see the same behaviour on hills too.

It’s also interesting to look at what’s called the gear ratios for each car, because that tells us a lot:

86/BRZ Transmission Ratios

Type

Six-speed manual

Six-speed automatic

Ratios: 1st

3.626

3.538

2nd

2.188

2.060

3rd

1.541

1.404

4th

1.213

1.000

5th

1.000

0.713

6th

0.767

0.582

Reverse

3.437

3.168

Final drive

4.100

4.100

The numbers such as 3.626 and 3.538 refer to the number of turns the transmission makes to one turn of the engine. In the case of first gear, the engine turns 3.626 times for one turn (revolution, or rev) of the gearbox. The final drive is the differential ratio, and it’s the same thing – in both cases, the input drive turns once, and the output of the differential turns 4.1 times. 

Both the auto and manual have the same engine, same differential (final drive) gears and apparently the same engine tune. It is not unusual for carmakers to tune engines slightly differently between auto and manual

What’s interesting here is the difference in gear ratios (gears 1-6) for each car. The numbers for the manual are higher than for the auto. This means the manual is lower geared than the auto, or in other words, for any given speed the automatic will be using slightly fewer revs than the manual. The reason the car is designed this way is because of the gearing effect of the automatic transmission’s torque converter. This also has an effect on fuel consumption:

Fuel consumption (L/100 km) *

Combined

7.8 (manual), 7.1 (auto)

Urban

10.4 (manual), 9.6 (auto)

Extra urban

6.4 (manual), 5.7 (auto)

with the automatic beating the manual across the board. This is because of the higher gearing and ability of the torque converter to maximise engine efficiency. It is true that the automatic is a bit heavier (about 23kg), and that torque converters lose some energy compared to manuals, but neither factor is (for the 86/BRZ) enough to outweigh the improvement in engine efficiency.

Let’s take a look at top speed too:

Performance

0-100km/h (s)

7.6 (manual), 8.2 (auto)

Max. speed (km/h)

226 (manual), 210 (auto)

What! The manual is faster 0-100, and has a higher top speed! There’s a couple of reasons why. First, for acceleration, the manual’s slightly lighter weight helps (1275 vs 1298 for the Toyota 86 in GTS trim). Automatic cars are usually a bit heavier than manuals because of their heavier gearbox. But 23kg can’t account for a half-second difference.

Second, at full throttle there is no advantage to the automatic transmission with its torque converter, and the straight-through, more direct and efficient manual has an advantage. But that doesn’t explain it either.

Finally, there’s gearing – the manual’s lower gears are more suited to a sprint. Both cars have to change to third just before the 100km/h mark. If the auto could top 100km/h in second it might beat the manual, which is one reason why we really need to start thinking about 0-150km/h sprint times more suited to the performance of modern cars. Gearing is the real reason the manual is quicker than the auto.

As for top speed, that’s also gearing. Weight doesn’t make much difference to top speed, it’s more about drag but here the drag coefficient of both cars is 0.27. The peak power is the same too, so it’s all down to lower gearing. Sixth gear is lower in the manual, and as cars are designed to reach their maximum speed before they hit the redline in top gear, then the manual’s lower gears means it gets a bit closer to redline in top than the auto, producing more power at the wheels, so it can go that bit quicker. Note that for many cars, top speed is actually reached in one or even two gears lower than the top gear, not the case for the 86/BRZ with its sporty, closely-spaced gear ratios.

Related posts

The 86 Long Term tests


Robert Pepper

Robert Pepper

Robert Pepper is a motoring journalist, offroad driver trainer and photographer interested in anything with wings, sails or wheels. He is the author of four books on offroading, and owns a modified Ford Ranger PX which he uses for offroad touring. His other car is a Toyota 86 which exists purely to drive in circles on racetracks, and that's when he isn't racing his Nissan Pulsar. Visit his website: www.l2sfbc.com or follow him on Facebook https://www.facebook.com/RobertPepperJourno/