Originally Posted by windhund116

Chuck, It really depends on if the engine is responding to the throttle. Say you start off in 3rd, from a dead stop. And floor it... this loads the engine below its normal powerband. You'll noticed pressing the throttle harder or even backing off the throttle has no direct response from the engine. It's like cruising at 35 MPH in 6th and suddenly stomping down on throttle. You will get a big lag in engine response.

Lugging is loading the engine below its torque or powerband.

Originally Posted by Chuck S

So every time you floor it from a traffic light you're "lugging" the engine 'cuz you're not running 4000 - 4500 rpm (middle of the rpm band)? Not that anyone would ever do this but it seems like nonsense to me.

-- Chuck

Originally Posted by Slowcrash_101

My biggest worry is the increased spark knock that VTEC causes. Say your oil pressure at 4k with oil at operating temperature is 80psi - 17 psi, you're down to 63psi, that's a 15psi difference than at 6k + rpm which according to the graph is in the 70-75psi. At higher RPM you also have the added benefit of faster more turbulent air in the combustion chamber helping ignite the mixture faster reducing the tendency for spark knock. At lower RPM airflow into the engine is slower and less turbulent(hence the low cam), by opening the high cam too early you are increasing the likely hood of spark knock. Particularly since you're typically at WOT when you go into VTEC. You're practically lugging the engine at lower RPM. All the ingredients for low speed pre ignition are there, and if your car is an oil burner its even worse because oil reduces the octane of gasoline. So more spark knock pounding the rod and main bearings, and lower oil pressure reducing the hydrodynamic oil film. That's my reasoning, I could be wrong. Gernby blew a fair bit of motors IIRC.

Originally Posted by RolanTHUNDER

Yes exactly. When the load is too heavy for the engine to pull, that is lugging. VTEC is not going to help much there. 35mph in 6th gear then suddenly flooring it is lugging as you said (and that analogy can be applied at various speeds in various gears). Moral of the story, always use the gears effectively. Our cars are designed with short ratio gear boxes for a reason. Get that rev matching and heel/toe going!

Originally Posted by windhund116

My old mechanic told me NEVER lug a newly rebuilt engine. You can do more permanent damage lugging than over-revving. Best to keep running it through the gears. Varying RPMs. Not drive at one RPM range for long lengths of time. Change oil at 500mile intervals, for first 1000 miles.

Originally Posted by ES2K

Could this lugging debate be attributed to one's driving style and acceleration expectations? If a person drives to achieve best gas mileage, it's possible they never accelerate fast enough to realize that they are lugging the engine. If 3K or 4K rpm seems like high rpm to a person driving an S, I doubt that they truly experience the S's magic.