Hillclimbing - What's harder, revs or gas?

[Kurtatron]

My commute requires a climb of 2000ft each way. This occurs within 15 miles. The steepest grade is about 7%. I.E. Lowest gear for a cyclist. I've been of the mindset "Less revs is better." But my miata has double digit horsepower and torque. I really have to give it gas to maintain speed in 5th. At about 2500rpm, my acceleration also stinks.
What would you think strains the oil and motor more? Remaining in 5th and reduced revs or increasing the revs but less gas pedal?

 

[spasm3]

hard lugging of the engine is hard on the oil and the rod bearings. What rpm do you run in 4th on the hill?

 

[XS650]

If you are at 2500 rpm and the engine isn't pinging, it's hard to do any wrong.

If someone tells you your are lugging your engine, get then to define lugging.

 

[BobFout]

Originally Posted By: Kurtatron
My commute requires a climb of 2000ft each way. This occurs within 15 miles. The steepest grade is about 7%. I.E. Lowest gear for a cyclist. I've been of the mindset "Less revs is better." But my miata has double digit horsepower and torque. I really have to give it gas to maintain speed in 5th. At about 2500rpm, my acceleration also stinks.
What would you think strains the oil and motor more? Remaining in 5th and reduced revs or increasing the revs but less gas pedal?


Lugging with load is far worse than being at the appropriate revs with load. Downshift to 4th, see how that feels. If it doesn't feel good, go to 3rd.

 

[oilboy123]

I would say revving is better than lugging.

 

[BobFout]

Originally Posted By: XS650
If you are at 2500 rpm and the engine isn't pinging, it's hard to do any wrong.

If someone tells you your are lugging your engine, get then to define lugging.


It's more than pinging (How does pre-detonation happen when you lug?), it's sound and feel.

2500 RPM is way outside the powercurve of that engine. An auto would downshift 1 (maybe 2 gears) just to maintain speed, let alone accelerate.

 

[XS650]

Like I said

"If someone tells you your are lugging your engine, get then to define lugging."

 

[sw99]

Hmmm. Reminds me of when I drive I-70 west up through the CO mountains driving 75 in fourth gear up the passes. That poor little Subaru 2.2L... No lugging there.

 

[beast3300]

Pulling the grade is much better than lugging it. If it can do it 4th with the ability to accelerate with increased throttle then I would use 4th. If not, 3rd.

 

[tomcat27]

it's better to use revs than to run at lower rpm and make the engine really work.

 

[Steve S]

The engine should sound happy.

 

[Gary Allan]

You're not lugging it. I'd probably be of the drop it back to 4th persuasion.

 

[river_rat]

I like to run halfway to the redline or a little more up hills at highway speeds. If pushing the gas yields zero acceleration, I downshift one.

 

[HTSS_TR]

Originally Posted By: river_rat
I like to run halfway to the redline or a little more up hills at highway speeds. If pushing the gas yields zero acceleration, I downshift one.

I agree.

 

[expat]

At what rpm does your engine produce maximum torque?
I'm thinking, gear down and run about 3k rpm.

 

[rationull]

I climb a similar hill (7% grade, not as much elevation change though) every day with my Civic. Torque peak is at 4300 RPM. I climb in 4th gear (out of 5) at 3500-3750 RPM generally. That's between 60 and 70 mph.

I'm not sure I could even maintain speed up the hill in 5th at 3000 RPM.

 

[Velo_Fello]

I've had two Miatas. They prefer to be revved.

Speed for speed, you'll be creating the same power.

But if you have more revs, you'll have a greater flow of oil around the engine, and a lower load on your bearings.

I like that.

 

[chet2]

i would just go in 3rd or 4th gear and not over rev engine

 

[demarpaint]

Originally Posted By: river_rat
I like to run halfway to the redline or a little more up hills at highway speeds. If pushing the gas yields zero acceleration, I downshift one.


That's how I do it. Sounds to me like the OP should give 4th gear a try.

 

[NateDN10]

I'm in the "shift down a gear" camp, but depending on how much throttle you're giving it. If you're at or near WOT, it'll run a bit rich to avoid detonation. That's bad for gas mileage, bad for the oil, bad for the cat. Higher revs but lower throttle can be better.

How long is the steep portion of the hill? If it's short, I sometimes leave it in 5th anyway.