qwerty11

I've read and watched countless articles with back to back comparisons between the two engines. With very few exceptions, the two engines perform very close. Based on the hp/tq numbers, and common sense, this does not make sense. So honestly, what's going on here?

RubyFX4

I think its turbo related. They both have the same or similar turbos and that's what produces the speed and the torque! (IMHO)

Summers22

iTrader: (2)

I wonder if they leak the same amount of oil as well?

Siskiyou

I'm not sure wether it is bore or stroke that gives the size difference but the 2.7 may just be a faster reving engine to get it moving faster. Once you add a load then the size difference shows. Think of it like two football players, a small one and a large one, the little guy is going to get those legs moving quicker but when it comes to the power to block, the big one excels.

freman dave

I have one of each and neither leaks oil.

zx12-iowa

I tend to agree. as someone who has owned both, I'm shocked the 2.7 is as fast or faster to 60. but the 3.5 torque going up hills holding a gear or towing is very noticeable

engineermike

I've often wondered about this myself. The dyno numbers agree with the ratings though. Going by the livernois stock dyno runs the 2.7 makes 265 rwhp and the 3.5 makes 310. That's right where they should be, but I agree that the performance doesn't seem to indicate that.

Keep in mind as well that the pcm on these are all based on torque demand. In other words, the torque demand in the ecm is probably limited to 375 ftlb at 100% pedal, even if the engine is capable of more. Notice how flat the torque and hp curves are on some dyno tests. That's the pcm making it flat by limiting it to whatever ford said we get. So, you could come up with scenarios where you wind up with 375 ftlb from 2000-5000 rpm, which will perform better than 420 ftlb and a rapid drop off to 350. Just keep that in mind when comparing performance.

5.Bro

Look at the trap speeds. The 2.7 has the slowest trap speed compared to the 3.5 and 5.0

Brand

So they both leak the same amount of oil then.

excaliber

They are close in speed until you put a load behind them. Then the 3.5 shines and leaves the smaller 2.7 in its wake.