Number of gears question

[SuperBuickGuy]

Back in the day of 2 stroke diesels, 13 speed road rangers were the king. Cars had two speeds. Now, most trucks have 8 or so gears, and most cars have 6 (or more) gears.... I know the why - because the motors available needed more gears to stay in their power band - but with today's motors, why would you design cars with 6 speeds?

Or more to the point - in a super light car - say 2000 lbs wet - why would you need more then a 4 speed?

[ford141]

Re: Number of gears question

One word: Mileage.

The 6 speed can keep the engine in it's sweet spot with the torque converter locked in all driving situations to maximize fuel economy and efficiency.

And not all the trucks run 8-speeds. My dad's last Kenworth had a 525 Cummins with an 18spd. Lots of gear options available. Only the cheaper fleet trucks run 8spds, owner operators usually opt for 13-18 gears.

[SSChevyManiac]

Re: Number of gears question

I drove an '06 G6 yesterday, Grandmother's rental while her 3.4L V6 gets the usual coolant fixes, it was all locked up and in OD by 40mph. I could give it a lot of foot before it would unlock and downshift.

[squirrel]

Re: Number of gears question

mileage is a big part of it, along with maximizing performance with a smaller engine.

3 speeds is fine for me most of the time.

Last time I drove something with a 5 speed, I was all like "what the fluck is with all these damn gears?"

[Tazracing]

Re: Number of gears question

Back in the day of 2 stroke diesels, 13 speed road rangers were the king. Cars had two speeds. Now, most trucks have 8 or so gears, and most cars have 6 (or more) gears.... I know the why - because the motors available needed more gears to stay in their power band - but with today's motors, why would you design cars with 6 speeds?

Or more to the point - in a super light car - say 2000 lbs wet - why would you need more then a 4 speed?

the why is cafe and epa mpg rating.. and emmisions, a steady rpm is better on both counts,

[BigBlockMopar]

Re: Number of gears question

Modern wimpy car engines don't have much torque anymore therefore they need al the mechanical help they can get to keep accelerating the lightweight heap they're powering at a not-so-embarrassing rate.

[SuperBuickGuy]

Re: Number of gears question

okay, so why do gearheads put 6 speeds in their cars?

[BigBlockMopar]

Re: Number of gears question

They either have a wimpy motor, or just think it's 'tough' ...? ???

Squirrel's last sentence has been my thought aswell once or twice.

[SpiderGearsMan]

Re: Number of gears question

the german have seven speeds and no overdrive

I don't like 6 speed autos - they shift too much

[squirrel]

Re: Number of gears question

4 speed auto with a smaller engine shifts too much.

Powerglide...now there's a good transmission.

[daved931]

Re: Number of gears question

A six speed in a car is good if you have a little bit of torque and can deal with "lugging" the engine a little. It allows for a double overdrive and it's what allows Corvettes to get 28mpg highway.

I'm in charge of a fleet of trucks. We have a couple of smaller box trucks with 6 speeds and pretty much everything else is a 10 speed. I do have an 8LL out there, which is a real stump-puller but not much good for highway use. My two best delivery trucks are a pair of Freightliner tractors with 10 speeds and DD13 engines. Those things will pull a hill in 10th gear all day long.

Of course, we're hauling food which can get heavy, but rarely gets crazy when running 28' and 36' trailers. If you have a 53' trailer full of frozen food, that can break 44,000 pounds very easily. It's not uncommon to be worrying about weigh stations with 50,000 pounds of fries on board, ha ha.

[TheSilverBuick]

Re: Number of gears question

The points have all been made. Mostly to keep the engine in the sweet spot for mpg's and emissions, secondarily for the gear multiplication in peakier engines.

Like Spidey says, the Germans use the steep highway rear gears then run a bunch of high ratio transmission gears.

[tedly]

Re: Number of gears question

A buddy of mine had a 96 Cobra with a T56 in it (6 speed). It was a stout transmission plus he could take long road trips without busting his wallet. The higher gears also kept engine noise down in town, so less hassle from the cops and more suckers potential sources of income. ;D

[mustang13]

Re: Number of gears question

The points have all been made. Mostly to keep the engine in the sweet spot for mpg's and emissions, secondarily for the gear multiplication in peakier engines.

Like Spidey says, the Germans use the steep highway rear gears then run a bunch of high ratio transmission gears.

A guy named Doug Nash tryed that too ;D

Nothin' like the OD whine that comes from a Roadranger

The new V6 Mustang posts the high mileage numbers with a 6 spd auto, not the stick, as you would think. We have a couple new F150's with the 6 spd hydro, they work great in the hilly parts here in the northeast.

[oletrux4evr]

Re: Number of gears question

I swapped a TKO500 for my Super T-10 to gain what amounts to an "overdrive" with the 5th gear. The TKO is geared lower in 1st, and identical to the T-10 in 4th......gives me more off the line, and better mileage at cruise.