04-28-2008, 09:16 PM
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| Administrator | | Join Date: Mar 2008
Posts: 16
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 Pontiac G8's 3.6-liter V-6 Fuel Consumption
The following is a response from a retired GM Engineer concerning the 3.6L V6 G8 engine and MPG. Quote:
Regarding "Pontiac counts on new G8 sedan to rev up the brand" (April 7): You nailed it again.
General Motors' second effort at multivalve, dual-overhead-cam technology is equally as thirsty as the first. The 4.2-liter inline six (being produced in Flint, Mich.) and its five-cylinder cousin are both getting reputations as being pretty thirsty at the pump.
Granted, GM engineered the six for performance, the intent being to compete with Ford and Dodge V-8-powered SUVs, and it is successful in that way. The trade-off has been the dismal fuel efficiency almost universally reported by owners.
Now, replacing the out-of-date 3800 V-6 with the high-tech 3.6, GM is taking a hit again on fuel efficiency. Some hasty re-engineering and retuning are said to be happening none too soon. While it is a sweet, smooth, spirited engine, the 3.6 as a base engine in the G8 and others should at least offer comparable mileage when driven conservatively.
Surely its 0.2-liter displacement deficit isn't responsible for its having to work so hard that it loses out on gas mileage. No, again, it was tuned/engineered more for performance than economy, possibly not a worry except for the now-horrific escalation of fuel prices.
Direct injection and perhaps some judicious camshaft redesign for more cylinder filling at low speeds will help. That would not be the first time that an economy version of an existing engine was offered. No doubt it's a question of value added vs. cost added, as it must be.
| As they say at the track "horsepower isn't cheap".  |
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