New Powertrains: I'm A Believer

[mkaresh]

Agree with others, great write-up. I'd like to drive a 2007 G6 GTP, 2006 G6 GTP, and Aura XR back-to-back to see how they compare. My sense is that they might have improved the G6 a bit for 2007 based on lessons learned with the Aura, as the 2007 convertible I drove (with the 3.9) felt better than the 2006 GTP sedan.

When I drove the Saab Aero I experienced transmission flare a number of times. I believe this is the same problem that has Toyota swapping transmissions out of 2007 V6 Camrys. And I think it might be the same basic transmission, since Aisin is Toyota's transmission supplier.

One thing I do wonder about: the authenticity of the trim in the Acadia. It's just not like GM to use real aluminum. They're not even using it in the new CTS, and they use just a bit of it in the Corvette. I'll have to look further into this...

[killerrd2]

Nice write up Ghrank. I echo your thoughts exactly.
The next few years will be interesting to say the least.
Bring on the Torana to replace the G6!

Cheers

[CobaltSScrazy]

Yes the High Feature should be the new standard in all GM V6 sourced cars. It brings prestige, value when using economies of scale, and can be made to be a performer in any capacity. Can someone post a pic of brushed aluminum, actual aluminum, and 'fake' aluminum so we get an idea of what you are referring to?

CobaltSScrazy

[63GrandSport001]

I think that people are overly critical of OHV engines, they are long from gone and still have great use. For this I hope to see them around for a good amount of time, they have proven to not only be smaller and lighter then their OHC counerparts but also get better fuel economy in a day of $3.00 a gallon gas.

I drove two cars with the 3900 V-6 in it one was the Monte Carlo and the other was a Impala and I was very pleased with the engines. And Ive driven all kinds of OHC and OHV motors before, there is no reason to get rid of the OHV V-6 just modernize it a bit more.

I think that the bulk of the difference in the 3.6L HF V-6 and 3.9L HV V-6 comes from the tranmission and not really the engine. More gears will make the car shift smoother as the torque difference from gear to gear is smaller. Not only that but you will pick up performance and fuel economy at the same time.

A 3900 with VVT and direct injection could make a great amount of horsepower and torque. It could also be a great base engine in US Zeta cars such as the Camaro and Impala, it could probably easily make 275+BHP and mated to a 6 speed auto or 6 speed manual would get over 30MPG highway.

[DemonKnightDK]

IMHO, GM should have stuck with 90* engines. they just always seem to have a better torque curve and fuel economy than 60* engines. I mean the old 3.8 and 4 speed auto got on average 30MPG HWY, the 3.9 gets what 27? how and why dose a "technically" superior engine get worse? the 3.5 V6 is very close to the 3.8 in terms of feel and fuel usage. I think GM should just kill the 3.9 and move to using the 3.5 as base and 3.6 upscale even bring back the 2.8 for smaller cars. or even a cheaper base engine for stripper or fleet sales.

[VivienM]

Originally Posted by DemonKnightDK

IMHO, GM should have stuck with 90* engines. they just always seem to have a better torque curve and fuel economy than 60* engines. I mean the old 3.8 and 4 speed auto got on average 30MPG HWY, the 3.9 gets what 27? how and why dose a "technically" superior engine get worse?

Have you compared the gearing between the 3.8 and the 3.9?

Let's see here... 3800/4T65-E always has a 3.05 or 2.86 final drive.

3.9L/4T65-E in Impala has a 3.29. In Malibu/G6 it's 3.69.

My guess is that that's what explains the MPG difference...

[bcjohnso99]

Originally Posted by 63GrandSport001

I think that people are overly critical of OHV engines ... they have proven to not only be smaller and lighter then their OHC counerparts but also get better fuel economy in a day of $3.00 a gallon gas.

Really?

2007 Camry (3.5l/268hp) 22/31
2007 Accord (3.0l/244hp) 21/30
2007 Impala (3.9l/233hp) 20/29

OHV = Lowest hp, worst fuel economy (not a leader in torque either)

[VivienM]

Originally Posted by bcjohnso99

Really?

2007 Camry (3.5l/268hp) 22/31
2007 Accord (3.0l/244hp) 21/30
2007 Impala (3.9l/233hp) 20/29

OHV = Lowest hp, worst fuel economy (not a leader in torque either)

All but the Impala have 5 speed transmissions... or 6 in the case of the Camry.

[63GrandSport001]

Originally Posted by bcjohnso99

Really?

2007 Camry (3.5l/268hp) 22/31
2007 Accord (3.0l/244hp) 21/30
2007 Impala (3.9l/233hp) 20/29

OHV = Lowest hp, worst fuel economy (not a leader in torque either)

You are comparing a 4 speed Impala to a 6 speed Camry.........

You are also comparing a older platform thats going out to a new one and lets not even get into aero and gearing of the two vehicles...... The 3900 in the Monte Carlo got some 29MPG on the highway put out over 240BHP and had some pretty aggressive gearing all this with a 4 speed.

And the Torque advantage of OHV motors is really a 2 valve compared to a 4 valve. It just so happens to be that most DOHC motors are 4 valves (almost all infact) and most OHV motors are 2 valves. The advantage is in torque broadness which the OHC motors use expensive technology to overcome.

In reality though fuel economy actually has very little to do with the engine but yet the aero, gearing, and amount of gears have the biggest effects on fuel economy. All GM has to do is put some more money in their OHV V-6 engines and its worth doing so because of the cost savings, fuel economy gains, and broad torque curves to modernize the motors some more.

Can you think of a 3900 V-6 in the Camaro, G8, and Impala that makes some 275BHP mated to a 6 speed getting over 30MPG highway, the Camaro starting at $20,000?

[LAMRONH]

Originally Posted by VivienM

Have you compared the gearing between the 3.8 and the 3.9?

Let's see here... 3800/4T65-E always has a 3.05 or 2.86 final drive.

3.9L/4T65-E in Impala has a 3.29. In Malibu/G6 it's 3.69.

My guess is that that's what explains the MPG difference...

I'm sorry nobody at GM has phoned me regarding these odd gearing choices. I can be reached at 1-800-555-1212, ask for Mr. Wonderful.
They run a 2.86 on the Lucerne 3.8, probably the heaviest car pulled around by Iron Mike.
They put a gas-burner 3.29 cop car ratio on the up-power 3.9 in the lighter Impala, in a 3.9 that should be producing =/> torque at lower RPMs than the 3.8. Same statement in spades for the 3.69 Mali/GrandAm.
Why not run the 2.86 in the 3.9, which of all GM's passenger V6s should best pull a long gear?

[VivienM]

Originally Posted by LAMRONH

I'm sorry nobody at GM has phoned me regarding these odd gearing choices. I can be reached at 1-800-555-1212, ask for Mr. Wonderful.
They run a 2.86 on the Lucerne 3.8, probably the heaviest car pulled around by Iron Mike.
They put a gas-burner 3.29 cop car ratio on the up-power 3.9 in the lighter Impala, in a 3.9 that should be producing =/> torque at lower RPMs than the 3.8.
Why not run the 2.86 in the 3.9, which of all GM's passenger V6s should best pull a long gear?

The interesting thing is to notice the trend.

Regal LS had a 3.05. LeSabres without Gran Touring had 2.86; with Gran Touring had 3.05.

Now, GM replaces both... and the 2005 and 2006 LaCrosse/Allures have 2.86 (the 2007 has 3.05 again), and the Lucerne goes to 2.86.

I suspect that GM beancounter thinking was that the 3.8s in the Buicks are the base powertrain (unlike in their predecessors), therefore tune gearing for economy (and anybody who wants performance can get a 3.6 or Northstar), while the 3.9 for the Impala is the 'mainstream' performance option (the 'extreme' performance option being obviously the 5.3L) so it needs somewhat more aggressive gearing, and the 3.9 for the G6/Malibu is REALLY sporty, so it gets the 3.69.

But yes, this is not necessarily the wisest move...

[LAMRONH]

Originally Posted by VivienM

The interesting thing is to notice the trend.

Regal LS had a 3.05. LeSabres without Gran Touring had 2.86; with Gran Touring had 3.05.

Now, GM replaces both... and the 2005 and 2006 LaCrosse/Allures have 2.86 (the 2007 has 3.05 again), and the Lucerne goes to 2.86.

I suspect that GM beancounter thinking was that the 3.8s in the Buicks are the base powertrain (unlike in their predecessors), therefore tune gearing for economy (and anybody who wants performance can get a 3.6 or Northstar), while the 3.9 for the Impala is the 'mainstream' performance option (the 'extreme' performance option being obviously the 5.3L) so it needs somewhat more aggressive gearing, and the 3.9 for the G6/Malibu is REALLY sporty, so it gets the 3.69.

But yes, this is not necessarily the wisest move...

"Beancounter thinking" should go in the oxymoron dictionary.
Beancounter thinking is one of the chief ingredients that put the Americans on the road to ruin.
As I have ranted on occasion, I think corporate America should take a good look at their MBA-is-god-think before ditching 90% of same.
If I were in the market for an Impala, I'd be taking a serious look at the 3.9, which is producing almost exactly what I think the 3.8 could--should--have been making around 2002 when the 03 Accord 240 HP 3.0 V6 came on the scene like gangbusters.
And if I were looking at a non-V8 Impala, it would need a 30 MPG highway rating, or very near.
The 27 MPG is way down in Mitsu/Chrysler/Ford territory, and I expect much better of GM.
Some day I will learn to not expect so much.

[VivienM]

Originally Posted by LAMRONH

"Beancounter thinking" should go in the oxymoron dictionary.
Beancounter thinking is one of the chief ingredients that put the Americans on the road to ruin.
As I have ranted on occasion, I think corporate America should take a good look at their MBA-is-god-think before ditching 90% of same.

Yup...

It's funny how corporate America thinks their MBA culture (and Wall Street) is the holy grail of management, yet it seems foreigners outdo American competitors in a lot of sectors... and largely by following methods that would make American MBAs scream.

But hey, it's not the MBAs' fault that they have pesky unions, manipulated currencies, and whatever other excuses they come up with to cover up the fact that the American MBA church-of-quarterly-results destroys companies like automakers...

[63GrandSport001]

I think its funny but based on the new ratings for 2008 the 3900 V-6 Impala is rated for 26MPG highway and so is the V-6 Honda Accord which has a 5 speed (compared to the Impala's 4 speed).

The 3.5L Toyota Camry has dropped down to 28MPG on the highway which is still impressive as it makes some 28 more BHP then the Accord yet gets 2MPG better on the highway but there are two factors here one is aero and the other is gearing.

[Michael_S]

Originally Posted by cmutt

4) GM's pushrod V8's. I'm talking about the truck engines (not the 'vette). Toyota's new 5.7l has matched (or slightly bested) GM in terms of balance of hp/torque/gas mileage -- an area where GM has virtually *always* been the leader. Is GM going to let it's foreign rival get a foothold in the market or is GM going to up the ante and tweak these engines for something a bit more than they currently are?

GM has a competitive truck engine, the 403 horsepower/417 pound feet 6.2 liter pushrod beast that's in the Sierra Denali, Yukon Denali, and Escalade.

The problem is, you can get the Toyota 5.7 liter engine in a $25,000 Tundra regular cab. The cheapest GM model with the 6.2 is a $38,000 Sierra Denali - and you can't even get the heavy towing package on the Sierra Denali.

Presumably the 6.2 will be available on lower trim level Silverado and Sierra pickups as part of the heavy tow package within a few years. The sooner the better.