This is a non LR question, and should probably be in another section, but here goes: A coworker and I were talking about engine sizes, specifically a 4.9L straight V6 and a 4.6L V8. Which one of these would get better gas mileage? My limited knowledge of engines makes me think that it should be the obvious smaller cylinder V8, but he thinks its the V6 that gets better mileage. What'd you guys think?

 

Straight v6 is a contradiction.

There are too many other factors in play to answer this question. You'd need to know about the gearing, transmission, weight of the vehicle, etc.

 

Soo many variables.
I would bet the V6 too.
More torque should give it an edge.

 

You can not compare mileage based on cubic inches, it has to be based on the design of the engine, it's fuel management system, cam, compression and lots of other stuff.

 

Yep, my 3.8 liter V6 Kia Minivan gets 23 mpg. 4.0 Disco 1 don't. But there is a lot more at work than just two cylinders and about a half a Coke can difference in displacement. The aerodynamics of a brick at 70 mph perhaps....

 

All things equal the V6 will get better MPG.

This might help.
Read the specs.

 

The v8 will get better gas mileage. That little v6 will have to work it's *** off to move the heavy Rover. An inline 6 in a jeep wrangler gets better mpg's than the little inline 4 engine for this reason.

It is also the same reason the newer 4runners went with bigger engines.

 

The problem we have here is that we know nothing about these engines as far as their efficiency. Also people are over looking that in the case provided to us, the confused V or is it straight 6 has a larger displacement than the V8.

EDIT: I wonder if the engine is question is the Ford 300? That's a pretty decent engine for it's day.

 

4.9 liters is 300 c.i. so I think you're correct. (and it is a good, low rpm torque engine. I've had a few of them over the years.)

 

Those Ford straight 6 engines are very durable. My Dad has one with 225,000+ miles and the engine itself has never needed anything other than maintenance items like spark plugs and wires.