I didnt bring this up as a pushrod vs. ohc debate so please dont go there . Im for the better engine whether it pushrods or whatever . While I havent driven a car with 3.6 vvt engine it , every car Ive read about that has this engine ....there has been nothing but praise . One quote going as far to say that "this engine improves every GM car its installed in " , " This is an engine to rival honda , nissan and toyata's V6's " . I guess what I dont get is why does GM have to use so many different types of V6 engines , including a HONDA V6 in one model ? Would it not be cheaper to just use the VVT engine in various power outputs across the board ? Just something I was thinking about .

 

GM's arguement is cost. I don't agree with the decision, though.

 

GM is slowly moving to 2 types of V6 engines for cars called...

High Feature = 60° 4v DOHC VVT 2.8L & 3.6L
High Value = 60° 2v pushrod 3.5L & 3.9L (DoD & VVT on 3.9L) 3v heads coming soon.

The HF egnings are being used in the more expensive cars, HV is the value Chevy and Pontiacs.

the HV pushrod engines cost about $800 less to build than a DOHC HV V6. It cost about the same for GM to use the 300HP 5.3L V8 as it does the 260HP 3.6L VVT V6's.

The 90° 3800 V6, 3.4L 60° V6 and 54° DOHC Opel V6 are slowly going away.

The 90° pushrod 4.3L V6 in trucks will eventually be replaced by the 275HP 4.2L DOHC VVT strait 6 from the trailblazer.

 

I would just guess they are slow to ramp up production. Like Z28X said, a few engines are GM has are on the way out and some might be replaced by the 3.6L.

3.6L is in: CTS, SRX, Rendevous, Lacross, umm.....yeah it does need to get around more. Damn the cost!

I'd also like to see the 2.8L HF in more products too but thats even newer, so it will take awhile.

 

Also, keep in mind Chevy and Pontiac LIKE to use the cheaper engines because of the lower cost. Wanna know one of the little-known things that contributed to the death of Olds?

Olds division bore the ENTIRE cost of development and production of the LX5 3.5 DOHC "Shortstar" engine used in the mid-'99-'02 Intrigue and '01-'02 Aurora 3.5. This engine was SUPPOSED to replace the 3800 company-wide. But, when Pontiac, Chevy and Buick saw what the added cost would do to the bottom-line on their versions of the W bodies? They kindly passed and kept the 3800 due to similar performance and superior MPG. They didn't care it sounded more refined. That helped make the Intrigue not nearly as profitable as it was supposed to be...

Just like with the Quad 4 in the '80s, Olds did the development on this engine...and a great engine it is/was. This information is from a GM dealer rep who visited us back just after the December, 2000 announcement to kill Olds. I cannot verify the accuracy of it...but it makes sense to me.

 

Every indication is that the 3.5l HV V6 is cheaper than the 2.8l HF V6, and that it is about as powerful and more fuel efficent. The 2.8 in the CTS gets only slightly better mileage than the 3.6 (EPA MPG numbers are the same, but L/100km numbers are slightly different), whereas 3.5l HVV6 applications get significantly better fuel mileage.
The 3.6 in the Buicks get better mileage, but they're down on HP and torque compared with the CTS.

 

True enough. I guess GM does't want it customers to have fun revving the 2.8L to 7100rpm (fuel cut off) either I was disapointed at the output of the 3.6L in FWD cars.

I wonder whats the price differnce between a HF V6 and a S/C 3800...and the gas mileage.

 

What's the output of each HF and HV engine?

 

HVV6:

3.5L = 200 hp/220 lb-ft
3.9L = ~245 hp/245 lb-ft

Plus excellent smoothness and fuel economy.

HFV6:

2.8L = ~210 hp/19x lb-ft
3.6L = 245-260 hp/240-250 lb-ft (depends on application/exhaust config.)

Other variants of the HFV6 ( ) will be out soon...

 

It looks to me as though the FWD cars' HFV6s are designed for better mileage. The Rendezvous gets better mileage than the CTS, despite weighing more. I wonder if there is actually a difference in valve timing.

 

FWD transmissions are usually more efficient on mileage.

 

Not significantly -- at most 1% or so. That doesn't begin to explain the difference.

 

The "Shortstar" was compromised from the beginning by poor engineering compromises. The beancounters nixxed variable valve timing, so the slide-rule wizards chose to go for a small bore/long stroke design for torque. Ironically, Nissan did the exact opposite with the VQ-series (big bore/short stroke with VVT). Guess which motor is still in production?

In the end, the "Shortstar" was short on horsepower, short on torque, and short on refinement. Ironically, this engine was originally slated for the Sigma-platform Cadillacs.


It wasn't a great engine, neither was the Quad 4 and neither was the Olds Diesel. The "Shortstar" was just another nail in the coffin for Olds.

 

Actually the linage of the engine is more like this...

3.4L DOHC V6 circa 1992 (most expensive V6 ever)>Northstar>3.5L shortstar>current 3.6L

Olds may have bore some development costs, but they are nowhere near the costs GM as a whole incurred on the initial 3.4L DOHC engine it is based on.

 

I was thinking more like $600, but still we're talking about an amount that's just a fraction of the $1,800+/car retiree health care liability.