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I drive a 2013 Fit, manual transmission. I shift by sound. When accelerating, I shift up when RPMs reach 3000. When decelerating, I have developed the habit of blipping the accelerator pedal to get 3000-4000 RPMs before engaging the lower gear. It's so automatic that I can't even remember whether I do this (1) while still in the higher gear, with clutch pedal down; (2) in neutral, with clutch pedal down; or (3) in neutral, with clutch pedal up. Maybe all 3, depending on whether I've been coasting in neutral before downshifting. This seems to have served me well in my last car (Tercel), which I never had to change the clutch or syncros on, and hardly ever the brakes (can't even recall if I ever did) before retiring it.

I've read conflicting information online about how long to drive gently for before driving with high RPMs. Some estimates ballpark the warmup time at 15 minutes -- that would be a pain, as it is half my drive. I have three questions about this.

(1) Is shifting up at 3000 RPM "gentle" enough?

(2) Is blipping the RPMs into the high 3x00's harmful?

(3) I hit th highway in less than 5 minutes, where I drive in the high 3x00's. Is this harmful? I don't drive erratically or with a high speed difference with the traffic in adjacent lanes, but I do drive in the high speed lanes. I don't look forward to being confirned to the slow-lane.

I used to think that, with the consistent viscosity of synthetic oil, 30 seconds of stationary warmup was enough (it's way more than required). But with what I've read, I'm wondering whether that warmup time is just to get moving, and whether I'm stuck having to stay in low RPMs for quite a while after that.

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I just drive normally but limit rpm to about 2.5k until the temp gauge starts to move or 10 mins then change around 3k as usual - but my max rpm is 4.5k as it is a diesel...

  • 2500 sounds reasonable (but I'm no mechanic). My Fit doesn't have a temperature gauge. It only has a low temperature indicator for the coolant. – user2153235 Mar 22 at 1:32
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Both the petrol engines available in the 2nd generation Fit are reasonably high-revving naturally aspirated i-VTEC units. 3,000 revs is well below the peak power and torque points for both and, depending the gradients you're driving on shifting there should keep the engine from laboring so I think it's a suitable shift-point if you're looking to be gentle. Once warm it's advisable to open the range up a bit.

Speaking of which the ~15mins time to warm up is probably about right - it'll vary a bit with the driving and traffic conditions but it's a reasonably safe number - the coolant will come up to temperature sooner but the key is to wait that bit longer to let the oil fully reach temperature. Come to think of it I don't think the Fit even has a coolant temp gauge, so I'd just stick to the fifteen minutes before using the full range.

So to specifically answer your question(s):

(1) Is shifting up at 3000 RPM "gentle" enough?

Yep.

(2) Is blipping the RPMs into the high 3x00's harmful?

No, if you're doing this to essentially rev match for down shifts then you are doing it with very little load on the engine. And the reduced wear benefits of doing so (on engine and transmission) will far outweigh any minuscule wear from the blip.

(3) I hit th highway in less than 5 minutes, where I drive in the high 3x00's. Is this harmful? I don't drive erratically or with a high speed difference with the traffic in adjacent lanes, but I do drive in the high speed lanes. I don't look forward to being confirned to the slow-lane.

Should be fine - assuming you aren't slogging up steep gradients this sort of steady-state driving doesn't stress things much - you're still below peak torque (let alone power) and you'll have some warmth in the system already.

  • While I generally agree with all the answers here, one thing that nobody seems to mention is that even though blipping the throttle with very little load won't be harmful at 4000 RPM, it's still more wear than idling at 800 or engine braking at 1600 RPM - simply because you've got more rotations, and because little load is still more than no load. If you can break out of the habit (only downshift when you actually need to start accelerating again), you'll be able to save fuel and eek out that extra 1% or so engine life. – Kitsunemimi Mar 21 at 13:58
  • @Kitsunemimi The rev-matching is more about saving wear on the gearbox/synchromesh. There's plenty of occasions where downshifting is a good idea even when there is no intent to accelerate again - however that's getting purely into the realm of driving techniques which are out of scope here. – motosubatsu Mar 21 at 14:03
  • Darn. I hit the highway in under 5 minutes on the return trip at the end of day. You're right, I have no temperature gauge. Only a coolant low-temperature indicator. I have yet to make deliberate observations, but I don't think it stays on for more than 5 minutes. I expect the oil warmup to correlate, but I don't know how well. And it's synthetic, which means more fluid even when cold. I'll continuing blipping on the downshift, but on your remark about gradients, I have instead the highway. About 3500 RPM. – user2153235 Mar 22 at 1:38
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So long as you don't spend all your time with the rev counter on the red line, I don't think RPM is so important as how hard the engine is working.

I take the same attitude as when running in a new engine. With a cold engine, don't push the gas pedal more than half way to the floor except in "unavoidable" situations - and most situations where you need to "accelerate out of trouble" are avoidable.

  • I've been trying to go easy until I hit the highway, ever since reading about the 15 minute warmup. – user2153235 Mar 22 at 1:31
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If you are downshifting, WHILE in neutral, you MUST have the clutch engaged to bring the driven shaft up to speed to match the rotation speed of the output shaft. Naturally, depress the clutch before engaging the lower gear!

Additionally, if you are using a 5W-20 oil, you will have adequate, whole engine lubrication within 5 minutes!

  • I totally forgot to pay attention on the drive today. Will keep an eye out so that I know what I'm actually doing.... – user2153235 Mar 22 at 1:40
  • This is a classic "double-clutch" shift, and will indeed bring the driven shaft up to speed and, if done correctly, significantly smooth the changing of gears. One may, however, improve a non double-clutch shift by slightly raising the engine rpm during the shift — without the in-neutral clutch release and repress. Doing so won't change the driven shaft's rpm, but will raise the engine speed and contribute to the shift's smoothness. OTOH, in a modern car driven moderately, double-clutching is not necessary. – David supports Monica Aug 18 at 18:15

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