Quote:
Originally Posted by mobyss
By the way - I've noticed that Cadillac in your posts - why did you get the small engine, and not the full-size 500 ci? ;-)
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hehe...in case it was a serious question; only the FWD Eldorado had the 500 ci (same engine just a crankshaft w/ more stroke). Later year Caddy's had the 500 ci, but lower compression and hp/torque!
Quote:
Originally Posted by roteague
Who says it isn't. Go back and some searches on the forum, rather than jumping to conclusions.
The system uses an electrically variable transmission with two hybrid modes of operation that optimize power and torque for various driving conditions.
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I think you're the one jumping to conclusions. mobyss was only asking because of the statement
I made. But I happen to be more right. There are 4 fixed forward gears. The continuously variable transmission is for the electric motors.
2008 CHEVROLET TAHOE SPECIFICATIONS
Drivetrain Front- or four-wheel drive, gasoline-electric hybrid
Base Engine 6.0-liter V-8, gasoline-electric hybrid
Emissions EPA/CARB Tier 2, Bin 5/LEV
Valves 16
Valve Configuration OHV, variable valve timing
Horsepower @ rpm 332 @ 5100
Torque, lbs-ft @ rpm 367 @ 4100
Transmission Two-mode continuously variable hybrid transmission, 4 fixed gears
Fuel Economy City/Hwy, mpg 21/22 (2WD), 20/20 (4WD)
Cruising Range, mi 525
Cargo Volume, cu ft 60.3 (with second and third row seats folded)
Fuel Capacity, gal 24.5
Towing Capacity, lbs 6200
Curb Weight, lbs 5617
Wheelbase, in 116.0
Length, in 202.0
Width, in 79.0
Height, in 76.9
Base MSRP $55,000 (est.)
This is a straight cut and paster from GM's press literature.
Here's some more from wheels.ca.com:
http://www.wheels.ca/Hybrid/article/47557
"Instead of the common hybrid use of a continuously variable transmission, GM uses what it calls a "2-Mode continuous electric ratio hybrid transmission" that has four fixed gears."
Car and Driver says:
"The transmission resembles a conventional four-speed automatic to which two 80-hp electric motors are integrated by marrying them to the transmission’s three planetary gearsets. Despite the two-mode name, the transmission, which fits into the same space as the automatic in conventional Tahoes, seems to operate in three distinct modes."
Quote:
Originally Posted by rob2299usa
wow except for roteague, you guys really need to do your research... the gm two mode hyrbids may have 4 fixed gear ratios but combined with the electric motors this creates an evt (electrically variable transmission). This basically allows it to have an infinite number of gear ratios between two fixed points.
"EVT's are capable of continuously modulating output/input speed ratios like mechanical CVT's, but offer the distinct difference and benefit of being able to also apportion power from two different sources to one output." -Wikipedia
There is a whole section under transmissions at wikipedia about evt's... check it out
http://en.wikipedia.org/wiki/Transmission_(mechanics) |
Boy this is fun....everyone is challenging me today it seems. Ok rob......I read
http://en.wikipedia.org/wiki/Transmi...28mechanics%29, did you...or did you only cut and paste the last sentence? Just because the "transmission" of the electrics motors is EVT, doesn't make the "real" transmission to the vehicle a CVT. Hell you want a good reference for the 4-speed AT GM uses on its 2-mode Hybrid....check out:
http://www.gm.com/shop/vehicle.jsp?y...1650&pvc=11651, click "view details at Chevrolet.com", click "standard and optional", then click "specifications", then click "transmissions". In black and white are 4 ratios! First gear = 3.69, Second gear = 1.70, Third gear = 1.00, Fourth gear = 0.73. And reverse isn't mentioned.....which makes sense because I read somewhere that the electric motors (and those crafty EVT transmissions) power the vehicle in reverse.