Do you burn more gas when you......
 

.....have more torque than horsepower?

i.e.

Impala SS 94-96
horsepower 260
torque 330

Bonneville SSEi 92-93
horsepower 205
torque 260

i would say no because it all depends on how the vehicle at question is driven...

It doesn't matter too much on the cars power. It's how you drive it.

Obviously though, a 405HP Z06 will burn a lot more gas than a 3400 or something.

You have to remember HP is derived from Torque x RPM / 5250.

So HP is only determined by what your peak Torque is like, and how much you have at higher RPMS (namely 5000 or more). Take this stuff here into mind...

L36 (205 HP 230lb/ft)
L27 (170 HP 225 ft/lb)

The 5ft/lb on the L36 is @ a much higher RPM then the L27. Since it's higher up, the equation for HP goes up, and gives you more horsepower. The L27 will beat an L36 off the line, all things being equal, but the L36 will come back because of it's revs. I personally think the L36 was given a HP over 200 to compete with other imports who have more HP then torque.

One other thing to consider is that not all cars need as much gas to make the same torque. A v8 putting out 300 ft/lbs will take a lot less gas then an I-4 making 300 ft/lbs.

Thats a good summary.

youd be suprised...

You also have to factor gear ratio, and weight.. Thats why the 405hp vette will get pretty damn good economy...If you keep your foot out of it, and keep it in the highest gear you can.

You can drive around in 4th gear easy in that puppy.

The first post in this thread compares a 350 V8 with a 3800 V6. That's comparing 5.7liters to 3.8 liters. Your PCM is producing an AFR in a very tight band, so naturally, the larger V8 will burn more gas than the V6 (at idle for comparison), simply because the bore is larger.