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Vk45de and vk56de
Posted: Tue Sep 08, 2015 3:31 pm
by lebanesepathy
Something confuses me about these engines, how come the way smaller displacment produces much higher horse power. Talking about 340 vs 310. And why use the 5.6 in the first place ? Is the higher torque really that important ?
Posted: Wed Sep 09, 2015 5:21 am
by smj999smj
When you are talking about a 4000+ pound truck which may be used for towing, "yes," higher torque IS that important!
Posted: Wed Sep 09, 2015 8:25 am
by skinny2
The power curve peaks considerably lower on the 5.6L as well. It has about the same torque at 2,500rpm as the 4.5L at 4,000rpm.
Posted: Thu Sep 10, 2015 12:18 pm
by smj999smj
Sometimes it's just a matter of cost to manufacture or a matter of a particular design being better when it comes to passing emission standards. For example, the SR-series is a fantastic, 4-cyl. engine, so why replace it with the QR-series, which has shown to be less reliable and have less performance potential? The cost of manufacturing for the QR is a lot less. The bottom line has a lot to do with the decisions manufacturers make.