Is lugging ok
 

I just need some confrimation on this. Is it more fuel efficient to lug a car with full throttle in 5th gear up a hill VS. normal throttle in 4th gear?

Is it ok on the car to lug it at lower rpms (like 1,500 with full throttle)?

it's probably more fuel efficient in 5th vs 4th.

But if the engine is lugging (1500rpm in 5th, uphill, in a saturn), you're being pennywise and pound foolish, I'd rather burn a little bit more gas than replace an engine every few months.

My cousin has a '01 SC1 and anything below 1500 in 5th and 1400 in 4th on flat ground the engine is starting to "lug". I'd use "normal throttle" in 4th gear.

think of it this way...

1200 rpms engine load is at 40 percent (30 mph) and i'm getting more than 60 mpg on the scangauge

i'm on the highway and my engine load is at 50 percent (60 mph) and i'm getting less than 45 mpg on the highway.

keep in mind for the first scenario i'm maintaining or bleeding off speed (30,29,28)

for the second scenario i usually try to maintain speed but if there's no one behind me i'll strat bleeding. But at rpms that high when I bleed it down back to 2000 rpms, I just start regaining speed again slowly... you can call this "healing" your speed again ;) and with my car anything above 2000 rpm it can pull decently no need to shift into higher gear.

think of it this way:
the higher the rpms the more oil pressure
there is a point where the rpms are not high enough to produce enough oil pressure and then your rings go bad quicker. and then your mpg really sucks cus you lost compression.

It's not the oiling that messes up the rings, it's the combustion. Lugging is when you're running too slow with too much throttle, and it starts to gag instead of pulling smoothly. It won't save much gas, as you're wasting it on poor combustion instead of power (the efficiency drops). More importantly, you get pressure spikes and high temps that cause all sorts of nasty stuff to happen.

Basically, if it's still smooth and giving it more gas makes it pull harder, you're OK. If it's making noises, and the gas doesn't do much, you're pushing it too hard and should downshift.

Randy, Dan (krousdb) on here has proven that no matter how much you lug the car speed will go up with lower speeds/rpms in 5th gear, regardless of how inefficient the engine gets, ;)

no im not saying that the low oil pressure is causing the lugging im saying that the low oil pressure is caused from the lower rpms and its not good for the engine as a whole, including the rings, because if they are not properly lubricated they will wear out faster, like everything else. it really does depend on the motor though, my car HATES being driven under 1600rpm others do ok in that range.

It's not an oil issue, it's detonation also known as pinging. It will knock holes in the top of your pistons, micro weld the rings. break ring lands, and knock out bearings. Like was said, if it's pulling smooth and no pinging, you're probably OK.

i dont think its pinging, its just when the 4 cylinders arent spinning fast enough the vibrations become very evident.

I have read somewhere that very light pinging was normal. I think it was in an owners manual.

When I lug my mom's engine it is not pinging or anything like that. I think it's just the engine not having it's balancy crap, but I'm making that up.