Gojirra99

Friday, August 19, 2005

Automakers tweak transmissions to gain an edge

By Joseph B. White / Wall Street Journal


In a quest for a new kind of competitive edge, automakers are pouring billions of dollars into creating cars with six, seven or possibly even eight forward speeds.

The burst of investment in automatic transmissions with more than the traditional three or four gears is being driven by growing demand for better fuel economy, as well as car makers' need to outdo rivals in a crowded market.

Mercedes is moving to offer seven-speed transmissions in most of its new models. Volkswagen AG's new Jetta compact car offers a six-speed automatic transmission as an option. Ford Motor Co. will soon offer a six-speed automatic on its Explorer sport-utility vehicle as part of a design overhaul for the 2006 model this fall. In addition, "Ford has got a lot of six-speeds in the pipeline," says Craig Renneker, Ford's chief engineer for new automatic-transmission programs.

Toyota Motor Corp.'s Lexus brand is going even higher. It is working on an eight-speed automatic transmission, industry executives say. A spokesman said Lexus wouldn't comment on any future product plans.

General Motors Corp. _ racing to catch up in the gear wars _ is working with Ford on a new, jointly designed six-speed transmission that will start appearing in GM vehicles in 2006. By 2010, GM plans to produce three million six-speed transmissions a year, up from a projected one million by 2008, says Tom Stephens, GM's group vice president in charge of world-wide powertrain operations.

With more gears, automakers are able to eke out improvements in fuel efficiency while advertising a sportier performance. In a six-gear system, the low gear delivers more power when launching from a stop; the high gear allows the car's engine to cruise with less effort at highway speeds, saving gas. Mr. Renneker compares the effect to the three-speed and 10-speed bikes he once had. With the lowest gear on the 10-speed, "you could climb a very steep hill," he says. Meanwhile, with the top gear, "you could get the bike going a lot faster."

The fuel savings vary by the type of vehicle, but Casey Selecman, an analyst at market researcher CSM Worldwide Inc., says going from four speeds to six can yield an improvement that can range from 3 percent to 7 percent. For a vehicle that averages 20 miles per gallon, that can boost mileage to 20.6 to 21.4 mpg. Averaged over a 15,000-mile year of driving, the fuel savings could be as much as 50 gallons, or more than $100. That's not a lot, but with car makers under pressure to improve their fuel-economy figures, incremental gains can add up.

Overall, the trend represents potentially billions of dollars in investments in engineering and new production equipment. GM and Ford have jointly invested more than $700 million in their joint transmission project. By 2010, the number of vehicles assembled in North America, Europe, Japan and South Korea with five-, six- or seven-speed transmissions could reach about 10.8 million, up from an estimated 5.7 million this year, according to CSM Worldwide. But in North America alone, the share of six-speed automatic transmissions is expected to rise from just 3 percent of production now to 40 percent by 2010, Mr. Selecman says.

There is substantial disagreement, however, over when more gears are better for drivers. A spokeswoman for DaimlerChrysler AG's Mercedes-Benz, which is rolling out seven-speed transmissions on several of its new luxury vehicles, says seven-speed transmissions help improve fuel economy and improve acceleration. They also help to reduce engine noise, because the additional gears allow the engine to run at lower revolutions per minute on the highway.

Other automakers say more is not necessarily better. Beyond using the number of gear speeds as a marketing tool _ "We have seven and somebody says 'We have eight,' " _ GM's Mr. Stephens says there's no significant benefit in terms of fuel economy to pushing beyond a six-speed automatic transmission. Mr. Stephens is also skeptical of continuously variable transmissions, which use belts and pulleys instead of gears.

Another issue, says Ford's Mr. Renneker, is that consumers may not like the way these new, plus-gear transmissions drive. "That's my biggest concern, that customers will feel it shifting too often," he says. "We are continuing to work to refine our shift busy-ness."

Some companies are going slow on upshifting to six-speed transmissions. Honda Motor Co. executives say for now they're satisfied with the performance of the company's five-speed automatic transmissions. It's not that Honda engineers aren't experimenting with a gearbox with a higher number of gears, company executives say, but they see going beyond the five-speed transmission now offered on the Accord, the CR-V, the Pilot, the Odyssey and the Acura MDX as unlikely to offer the kind of fuel-economy benefits that the cost of such a project calls for.

At the Chrysler Group, DaimlerChrysler's U.S. mass-market unit, the company is phasing in five-speed automatic transmissions in its popular Chrysler 300 C sedan. Its minivans, such as the Dodge Caravan, currently ride with four-speed automatics. "I don't think consumers are counting how many forward gears they have in the transmission," says Steve Bartoli, Chrysler's vice president for strategy. "But they do understand how they feel about a performance level ... and they're gaining more awareness of fuel economy."

Balancing those needs can mean using different technology in different vehicles, he says. "There's not one canned answer."

source : detnews
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Xerokool had posted a Taiwan article mentioning a new 8 speed transmission for the new LS . . .

np20412

Read that article in Wednesday's Personal Journal Good read, further making me a believer that Lexus will develop the first 8 speed auto-tranny.

XeroK00L

Thanks AmethySC for the article. The fact that WSJ bothers to report this really means something. Seems that the article I posted earlier regarding the next LS could be valid after all.
https://www.clublexus.com/forums/sho...d.php?t=168678

I'm really looking forward to seeing this technological wonder come to fruition. Go Lexus!

EDIT: BTW, here's the link to the article AmethySC posted:
http://www.detnews.com/2005/autosins...uto-286278.htm

np20412

WSJ has a section for Cars every Wednesday or Thursday, and usually everyday you can find some articles relating to the automotive industry, since it is a rather large part of our economy.

mmarshall

25 years ago in the early 1980's the Mitsubishi Mirage was sold here under the name Dodge / Plymouth Colt with a so-called " twin stick " manual transmission ( with two separate levers next to each other ) that was really 4-speed manual transmission and a two-speed final-drive unit......each shifted separately...... for a total of eight possible forward speeds. Those older members of CL will probably remember it.

SoCalSC4

Ouch. I do remember these... they had a "Power" and "Economy" setting for the final drive if I recall. My friend Mike had one back in high school.... funny little car. He would get pissed because my '78 Fiat 131 Super Brava (1756cc twim cam 5-speed) would SMOKE him. The Colt's "Power" mode could note overcome the greatness of the Fiat twin cam!

Of course, modern CVT transmissions basically have an infinite number of gears. I drove a CVT-equipped Audi A4 when they came out. Punch it, the revs increase and stay where the computer thinks horsepower & torque work best- then it slips through the gears as the car accelerates. Very strange sensation.

jrock65

Very good article.

So I guess the jury is still out on whether adding more gears is necessarily better, after 5 or 6 gears.

XeroK00L

Adding more gears definitely helps fuel economy and lowers engine RPM at cruising speeds and hence noise. Acceleration might be hampered by the need to change more gears, but definitely helped by a lower 1st-gear ratio and closer gear ratios. And has anyone complained about feeling too many gear shifts in the new 7-speed Mercedes cars during acceleration? I think not. Everyone compliments on how smooth the 7-speed is.

I vote for more gears = better.

P.S. Unless your name is AMG and need to handle 700+ ft-lbs of torque.

jrock65

More gears do help mileage, but by how much? According to the article, going from 4 to 6 gives you 3 to 7% better mileage.

So if going from 6 to 8 gives you 2% better mileage (guessing here), but adds to the cost of a car $1000, I'd say it's not worth it.

Also, almost all of the audible noise at highway cruising speeds comes from wind and road noise. I'm not sure that lowering the rpm, say, from 2000 to 1800 is going to matter any.

Hey, if extra gears can be put in for real cheap (like $50 per car), then I'm all for it.

I see the makings of a "gear war", just like the "horsepower war" we have ongoing right now.

np20412

Hence the name of the article

Gojirra99

Can a 8 speed transmission handle the LS600h's supposedly 500+ hp & the same huge torque then? or the 8 speed(if indeed true) will be limited to the new LS460 (or is it LS500 ? ) ???
All of the AMG versions by Benz still have the 5 speed now, since their 7 speed cannot handle the torque & their use were limited to their "regular" models.

Gojirra99

The law of diminishing returns always apply to increase in bragging rights, whether it's # of gears, hp, luxury . . .

XeroK00L

My bet is that the 8-speed will be applied only to the petrol-only LS and the hybrid LS will get the CVT as do all other hybrid vehicles on the market so far.

Gojirra99

Can the CVT handle the huge torque ? The RX400h, & even the GS450h will still have the equivalent of < 400hp & torque

XeroK00L

<400hp yes, but the peak torque of the electric motors is much higher than that of typical gas motors. If Lexus' CVT can already handle the peak torque of the electric motors in the RX400h and the GS450h, I don't see why it can't handle the LS600h's.