4 speed vs 5 speed

**maria** · November 6th, 2007 02:27 PM

pls help me understand the difference between 4 speed & 5 speed vehicle, and its 'pros & cons'. thank you

**sboogie** · November 6th, 2007 02:52 PM

sa experience ko
4 speed mas may torque kaso bitin sa top speed and maiksi ang gear shifting
5 speed mas mataas ang top speed and mas mahaba ang gear shifting

**boybi** · November 6th, 2007 03:07 PM

Mas maraming speed, usually mas matipid sa fuel consumption since the engine won't have to rev higher to achieve a certain speed.

**niky** · November 6th, 2007 03:13 PM

It depends.

Depends on how long the gears are, whether they're both manual or both automatic or whatever.

Basically, the more gears you have, the longer you can stay at a certain rpm while accelerating.

For example, in a 4-gear car (this one's a Lancer GT)

Speeds at 1000-2000 rpm per gear
1st gear: 10-20 km/h
2nd gear: 19-38 km/h
3rd gear: 29-58 km/h
4th gear: 40-80 km/h

Whereas, in a 5-gear car (Lancer ES, MT, same engine)

Speeds at 1000-2000 rpm per gear
1st gear: 9-18 km/h
2nd gear: 16-32 km/h
3rd gear: 23-46 km/h
4th gear: 30-61 km/h
5th gear: 41-82 km/h

A four gear box gives you long gearing, which makes for good highway economy, but since each gear has to cover a wider range of speeds, either you accelerate slower or use more power to get up to speed.

A five gear box gives shorter spacing between the ratios, so you can accelerate more quickly at the same revs... which gives you better fuel economy in the city.

This is as long as we're talking manual versus manual or automatic versus automatic. If it's manual versus automatic, your standard 4-speed automatic box will always give worse economy in the city, as, beside the longer gearing, it's also heavier and takes more power from the engine to operate than the manual.

The opposite is true of the CVT. Some CVTs are almost as light as manuals, and because they have no fixed ratios, you can stay at exactly the same rpm the entire time you're accelerating, which is the most fuel efficient method of using a gasoline or diesel engine.

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BTW, a six speed transmission is even better, but once you start running that many speeds on an econo-box, you get some ridiculously short gears...

**mbeige** · November 6th, 2007 03:46 PM

I support what Niky said, the exact principles (depends on the gearing) came to mind.

Consider that fifth gear as an overdrive to reduce engine RPMs at high speed to minimize fuel consumption. Four speeds also have an overdrive, but comparing the ratios, that fifth gear will almost always yield better fuel economy.

**rion** · November 6th, 2007 10:35 PM

self theory: for m/t, the many gears you have, the longer it takes you to reach 100km/h.

kasi nga, a lot of power is lost between shifting those gears... hehe...

**kokey** · November 6th, 2007 11:02 PM

Kung AT car mo e mas smooth pag 5 speed sya.

--------------------
"It's not fun to own a LEMON"

Think twice before you buy a HYUNDAI.

**niky** · November 7th, 2007 12:03 PM

*rion: Not really.

What you're looking at is not the time it takes you to row through the gears, but the amount of power you're using as you accelerate in gear.

The shorter the gear, the easier it is for the engine to accelerate in that gear.

Here's a good example... take your basic mountain bike.

Start off in lowest gear (we'll ignore your front gearset and assume your rear-set is eight cogs)... As you start off, you don't have to pedal very hard... then shift, then shift, then shift... as you go faster, you're still using the same amount of power.

Now, if you have less gears... start off in 2nd... then 4th... then 6th... then 8th... you need to pump harder to get up to speed. So even if you lose less time to shifting, you're using more energy to move yourself.

Most modern 4-speed automatics are geared so that you lack for power on the road, but they have to sacrifice somewhere, and it's often in that first gear, which is much longer than on a 5-speed car. That long first gear makes the engine work harder from a stop... it's like starting your bike in 2nd gear... it takes more muscle to start the bike rolling, which is equivalent to more gas wasted in a car.

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Hell, thought of an even simpler example. Staircases. More stairs, with a shorter step height = easy climb. Less stairs with a taller step height = puff... puff... puff...

**5Speed** · November 7th, 2007 02:26 PM

Originally Posted by niky

*rion: Not really.

What you're looking at is not the time it takes you to row through the gears, but the amount of power you're using as you accelerate in gear.

The shorter the gear, the easier it is for the engine to accelerate in that gear.

Here's a good example... take your basic mountain bike.

Start off in lowest gear (we'll ignore your front gearset and assume your rear-set is eight cogs)... As you start off, you don't have to pedal very hard... then shift, then shift, then shift... as you go faster, you're still using the same amount of power.

Now, if you have less gears... start off in 2nd... then 4th... then 6th... then 8th... you need to pump harder to get up to speed. So even if you lose less time to shifting, you're using more energy to move yourself.

Most modern 4-speed automatics are geared so that you lack for power on the road, but they have to sacrifice somewhere, and it's often in that first gear, which is much longer than on a 5-speed car. That long first gear makes the engine work harder from a stop... it's like starting your bike in 2nd gear... it takes more muscle to start the bike rolling, which is equivalent to more gas wasted in a car.

-----

Hell, thought of an even simpler example. Staircases. More stairs, with a shorter step height = easy climb. Less stairs with a taller step height = puff... puff... puff...

sang-ayon ako sa mga paliwanag ni kapatid na niky....

**meledson** · November 7th, 2007 02:43 PM

Originally Posted by niky

*rion: Not really.

What you're looking at is not the time it takes you to row through the gears, but the amount of power you're using as you accelerate in gear.

The shorter the gear, the easier it is for the engine to accelerate in that gear.

Here's a good example... take your basic mountain bike.

Start off in lowest gear (we'll ignore your front gearset and assume your rear-set is eight cogs)... As you start off, you don't have to pedal very hard... then shift, then shift, then shift... as you go faster, you're still using the same amount of power.

Now, if you have less gears... start off in 2nd... then 4th... then 6th... then 8th... you need to pump harder to get up to speed. So even if you lose less time to shifting, you're using more energy to move yourself.

Most modern 4-speed automatics are geared so that you lack for power on the road, but they have to sacrifice somewhere, and it's often in that first gear, which is much longer than on a 5-speed car. That long first gear makes the engine work harder from a stop... it's like starting your bike in 2nd gear... it takes more muscle to start the bike rolling, which is equivalent to more gas wasted in a car.

-----

Hell, thought of an even simpler example. Staircases. More stairs, with a shorter step height = easy climb. Less stairs with a taller step height = puff... puff... puff...

Galing ng explanation!