My Ford Galaxy had 3, VW Rabbit had 4, Corolla 5, and many newer are configured w/6 speeds. But which is the best?
My opinion, 5 is a little better than 4, but not much. 4 is quite a bit better than 3. 6 seems like it would require too much shifting. So my preference is 5 , but I wouldn’t kick a 4 out of the bed for eating crackers. 3 and 6 are no-goes.
Several variables have to be considered:
It all depends on the power curve of the engine, weight of the vehicle, rear (or front) gear ratio, the HP and torque output of the engine, and when does overdrive (OD) come into play…
Most 3 speeds are just pretty basic, but 4 speeds can have a granny low and 3 normal gears, or 4 normal gears, or 3 normal gears with 4th being OD, but it can have a long 2nd gear… Most 5 speeds are 4 normal with 4th being 1 to 1 ratio and 5th being OD, 6 speeds depending are normal 4 speeds, but steep gears, with double OD’s ,meaning 5th and 6th are OD’s…
A Mopar A833 is a 4 speed, the old ones are normal with 4th being a 1:1, but around 1976ish, it became a OD with 2nd being stretched out, 3rd being 1:1, and 4th being OD, not good for racing…
Heavier cars can benefit from more gears, but big block torque monsters don’t need as many gears cause they have a long flatter torque curve…
A 6 speed in your Corolla would hardly use 6th unless you were going highway speeds and had settled into the drive so to speak…
I have owned 4, 5 and 6 speed manual cars. The 6th gear lets the engine loaf at low rpm on the highway. A very low 1st gear gives great acceleration but now second needs to be lower, too, so the shift keeps the power in the torque band. That means you need more gears in the middle between the low, low 1st and tall, tall 6th.
I did replace the 5 speed for a 4 speed in my Camaro racecar. While racing, I only used 3rd and 4th and the T10 4 speed was way stronger than my T5 5 speed.
Short answer… More gears are there for better acceleration and greater fuel efficiency. That is why there are 8, 9 and 10 speed automatics.
Well, in an automatic, a 3-speed with lock-up torque converter is best. You get a first gear with quick acceleration from a stop, a second gear with decent acceleration, and a third gear with adequate performance, followed by the lock-up torque converter engaging at around 45 MPH…which feels like a fourth shift up.
A 3-speed automatic transmission offers good performance, reliability, and fuel economy, as well as offering decent engine braking when you take your foot off the accelerator. Many of these transmissions do a quarter of a million miles or more without needing major repairs.
The close ratio 5 speed in my GTI was great for acceleration, but buzzed along at around 3200 rpm at 60 mph. Got 25 mpg in town and on the freeway. Sure could have used a 6th gear.
What was the newest 3spd manual you can recall?
Friends 82 omega had a 4 on the floor.
Every auto manufacturer disagrees with you. Physics disagrees with you, too.
A 4 speed auto is nearly obsolete. 5,6,8,9 or 10 speed autos all with lockup convertors.
Well, I have driven vehicles with automatic transmissions with more than 4 speeds…and they don’t work as well. My current work truck is a 2015 Ram Promaster 2500 cargo van, and the transmission is terrible. Harsh shifting, and poor performance have been an issue, and all of the software updates, etc. have been done. I think it’s a 6-speed. The 3-speed “Torqueflite” was way better than this transmission. It never needed software updates, either.
Don’t paste all 4+ speed autos because your Ram isn’t very good. The 92K mile 6 speed in my Mustang works very well, has engine braking and a lockup convertor. The 8 speed in our Audi may be the best auto I have ever driven.
Pretty naive question. Best for what? Considering that a transmission’s function is to transmit power to the drive wheels while keeping the engine in its most efficient RPM range, the transmission with the highest number of gears is best. Or a CVT.
Then there’s implementation. Or weight. Or strength. Or possible gear ratios. Or reliability.
The list goes on and on. Define “best”.
Pretty much like a lot of Topics George has started lately.
If you are asking me that question…
Best shift quality is a here and now trait. Smooth almost imperceptable shifts at the right times to keep the engine in its powerband. Good fuel ecomony and no service required. The Audi is that.
The Mustang also shifts well, but not as good as the Audi. The manual shift function works great. I have had to service it due to a failed sensor. So pretty good reliability for 92 K.
My 20 year old electronically controlled 4 speed auto in my truck still shifts great with 154K on it. Even though it has been drinking coolant from my failing radiator. A few flush and fills after radiator replacement and it seems OK. Pulled a LOT of trailer weight with not a single hiccup.
Had a work truck, granny gear for 1st gear, did not need it even for plowing.
More gears is always better from a performance standpoint. That’s why an infinitely variable transmission is desirable. Theoretically, it can allow the engine to remain in it’s most efficient operating band at all times.
From a drag racing perspective, more gears is the great equalizer. My car with a 5 speed was significantly faster than with the 3 speed. All else being equal. And the 5 speed was significantly heavier. It’s simple- lower initial gears allows the engine to get the mass moving more efficiently from a dead stop.
If you’re arguing that less gears are better, then it better be from a reliability perspective and even then, that’s getting harder to defend as the technology for up to 10 speed gear boxes becomes more ubiquitous and CVTs become more reliable…
The TorqueFlite is a great transmission and I love them, but they are not practical, 1st gear in the both the A904/998/999 and the bigger A727 was 2.45 for 1st gear, 2nd 1.45 and all 3rd’s in every 3 speed transmissions is 1:1 unless I am forgetting something, starting mid year1980 the A904 clan started running a better 2.74 1st and a 1.54 2nd gear and as all the rest modern day auto 3 speeds a 1:1 1st… the better gear set never made it to the A727… Lock up started mid year 1978… Helped a tad to lower RPMS at speed but not enough…
Unless running a big cube engine with a ton of low end torque the rear gear needs to be much lower ratio for it to get up and moving, that is not good for fuel economy, so you need the OD to help lower the engine RPMS at highway speed… Mopar added an overdrive to the tail shaft/housing of the beloved A904/A727 making it the A5000/A518, the OD with it’s 0.69:1 ratio (IIRC) helped lower the RPMS even more with the lock up… So reliability aside, the A500/A518 4 speeds were way better for fuel economy and lowering engine RPMS at highway speeds… All 3 speed autos are close to the same and greatly benefit from there ODs, GM’s 700R4 was a great example with a much needed low 1st gear, it added much better acceleration from a stop than any OE 3 speed every did…
Almost all long haul Power Tour vehicles that still have 2/3 speed autos run a Gear Vendors Under/Overdrive unit with it’s much needed 0.78:1 (22%) OD ratio gear to lower engine RPMS at speed…
Here is a chart of the different gear ratios for the RWD 3,4,5,6 & 8 speed autos from Mopar…
With my 3.91:1 rear gear (in the fun car) I desperately need an OD for the highway, and if I ever go to a lower gear like a 4.56:1 it will be screaming on the highway… Not good for long life… Big difference hitting redline a few times in a few seconds then back to idle, but an engine is not going to live long cruising at redline for very long…
Just to add a little to @davesmopar 's great post.
You can make up for a not-low-enough 1st gear with a loose converter to multiply torque and raise the engine’s rpm closer to m=the max torque point. Gives a great launch but adds a ton of heat to the ATF, feel weird (slushy…) when driving and hurts fuel economy sooo… A lockup converter solves that, right? Imagine trying to lock the loose converter while driving… it is going kick you in the rear hard… customers don’t like that… if you don’t soften the apply which them wears out the converter clutches.
More speeds eliminates that trade-off. Add 2 (or 7!) more gears, tighten the convertor and you help driving quality, a boost in acceleration and better fuel economy.
Thread is about manual trans.
Same principle for moving a stopped vehicle and fuel economy applies for both the manual and the automatic transmissions… Torque converter aside…
EDIT to spell principle not priceable… lol
