questions on manual driving

[bgd73]

look up specs for oil pump max pressure at its rpm. Take each gear to that as a minimum..
most often it matches torque rpm, but inlines are extremely offset, you need to look in the book mechanics usually have...
especially inlines, they need that max squirt between the gears. It will never ever be a low rpm "torquer" matching all parts together. the boxers for example..2850 is max torque and oil pump and progressive secondary...all at the same magical rpm..

If not to know or find out, at least 2800 rpm, and again, the inlines could be a universe apart within itself.

[Shaias]

I agree with not lugging your engine just to get better mpg. Personally I hate it when I cruise close to idle (say 900 rpm when the idle speed is 700) but my car feels pretty comfortable at say 1300. Plus the car starts to sort of misfire when you get at or below idle. However one thing I don't know is if it is safe to coast at idle while in gear when the engine doesn't seem to be struggling.

[jazda]

Hey guys, I recently just joined this forum and I was wonderinf If i'm doing my engine any harm by shifting at 2k and cruising aroudn 1.5k-1.8k. It's a 2.5 L 4 Cylinder 170 hp and 170 torque (mazda 3 2010 gs)

also would short burst of accelerations lasting roughly around 7 seconds maybe 3-5 x for my whole tank (round 50L) affect the gas mileage if i cruis around 1.5 to 1.8 k most of the time?

Im doing it for the reason of break in period, I was advised by a couple of mechanics i know to have short bursts of accelerations to help seat the rings(i know theres different theories about this but lets stick to mpg lol)

[Christ]

You seat the rings with heavy engine braking, not acceleration.

Yes, hard acceleration (especially WOT) will affect your mileage. Will you even notice it? Probably not. It's going to end up within the noise of day to day driving variations.

The theory behind seating the rings with hard accel is completely false, as far as I'm concerned. The combustion pressures don't force the rings against the cylinder walls, where they would scrape and "seat" themselves. Instead, you're making for short oil chance intervals.

Run the engine up to ~4500, then use the engine to brake slowly, rather than using the brakes. This is also more efficient, as you're not bleeding speed off as brake dust. You only need to do this a few times through the first couple tanks of gas, then change your oil soon after the first 500 miles on the clock. You'll almost inevitably see metal shavings in the oil, this would be the break-in of the rings.

The other option is just to drive responsibly, and don't race the engine or accelerate too quickly.

The third option is to do exactly the opposite, and when the engine blows up, tell the warranty department that the mechanics told you to redline your engine a few times a day.