Harmful to downshift causing 4k rpm?

[fc321]

I was driving at 40mph (in 4th gear) and downshifted to 2nd gear when I saw red light ahead.

Rpms climbed to a little over 4000 rpm as a result of this. Maybe it was 4500 actually

Is this harmful behavior? Is that pushing things too far?

I should also add that car was only driving for 6 minutes so not fully warmed up yet

[Loren]

Is this harmful behavior? Is that pushing things too far?

Not even close. Redline is 6500. Maybe it's not a bad idea to keep it under about 5000 when it's cold. But, these cars warm up fast. After 6 minutes of driving in Miami... it's pretty much warmed up.

If you revved out 2nd gear all the way to the rev limiter, you'd be going 54 mph. So, if you're going less than 50 and you downshift to 2nd, you're not going to hurt the engine at all, totally within its normal operating range. Might be a little hard on your clutch if you don't rev-match it. But, the engine will be fine.

Don't try going into FIRST gear at that speed, though! That's exactly what killed my engine. Top speed in first gear is around 30. If you grab first at 50+ mph... you're definitely over-revving the engine.

[kzelisko]

I would suggest rev matching on downshifts like that if you aren't already to save wear and tear on the clutch, but otherwise, as Loren said you aren't going to hurt anything.

[Pryme]

Or just drop it into neutral when coasting towards a stop light.

And in a quick stop you dont need to downshift. Just push the clutch and brake in at the same time. Let the brakes do their job.

[fc321]

Thanks guys,

The first year I owned this car (and I had not driven a stickshift in over 10 years) I used Neutral ALOT, I mean ALL THE TIME when going to a red light or even a stop-sign but this year I have been downshifting more often. In this case would downshifting into 3rd have been appropriate? Or just to go into Neutral? it took me about 5 seconds to get to the red light (that had just changed to red).

But maybe I should quit downshifting for the purposes of slowing the car down? I certainly dont want to wear out the clutch earlier than necessary.

I've never learned to rev-match. I thought that was for racers.

[Loren]

If you're into hypermiling, downshifting and leaving the car in gear as you coast up to a stop uses less fuel. (look up "DFCO") But, I've found that it's hardly worth downshifting to 2nd for that purpose. Just grab 3rd and coast down until you hit about 1100 rpm, then clutch in for the stop.

It's not a bad idea to "be in a gear" when your'e driving in traffic. Always ready to dig out of a sticky situation when it comes up. You just never know when something stupid is going to happen and you might need to ACCELERATE to get out of the way. Can't do that if you're in neutral.

As for rev-matching, it can REALLY smooth out your driving. It doesn't take much. Just blip the throttle when you clutch in for a downshift. Just enough to get the revs up close to where they will need to be after the downshift. Doing so makes for a seamless downshift that is easy on your clutch, your synchros and your gears, doesn't "upset" the car, and is just plain smooth. Try it!

I didn't used to do it until I got into track driving. Then I learned to do it. And, as mentioned, downshifting is good for hypermiling, so I downshift a lot. And I rev-match every downshift. It becomes a reflex after a while.

Without rev-matching, the car lurches forward when you downshift. With proper rev-matching, you should feel nothing.

[Pryme]

You can pretty much coast down in whatever gear you're in and drop to neutral not far from a stop, but even if you downshift you can get really good at just knowing the speed to do it without rev matching. Just do it a bit later than sooner if unsure. The only time I use rev matching is if I'm coming down a bit quicker for a turn.

I use neutral a lot. And the mirage is so light it slows quickly anyway. I'd rather use a tad bit of brake then clutch to slow down
Brakes are easy and cheap, clutches aren't.
And even if you're coasting down in neutral its ultra fast to snap it in gear and go if needed.

For extra credit and to try an advanced technique, try upsgifting without the clutch. I used to do it sometimes in my Mustang GT. If you hold the shifter with a bit of pressure against the next gear as you're accelerating it will slide right in when the gears match.

I have not tried with the mirage

[fc321]

For extra credit and to try an advanced technique, try upsgifting without the clutch. I used to do it sometimes in my Mustang GT. If you hold the shifter with a bit of pressure against the next gear as you're accelerating it will slide right in when the gears match.

I have not tried with the mirage

I do that on my motorcycle but I was afraid that would be harmful for the Mirage? My motorcycle has a sequential 6 speed gearbox so when i am in gear 3 .. I am able to upshift to 4, 5 and 6 without using the clutch but I was not aware we could do the same on the Mirage without causing any gear-grinding or slippage.

I thank you all who have commented, your input has really put me on the right track because I am trying to save fuel and to extend the longevity of the car's components as far as possible. It sounds like I was making some mistakes, thank God it is only 15,300 miles on my car so far so I hope I have not caused too much damage with my misguided downshifts into 2nd gear to invoke engine braking. I have done that maybe 40 times total.

One last question. In the same scenario of travelling at 40 mph, If I see light changing to red up ahead is it wise to downshift to 3rd to slow the car down a bit? Or should I just stay in 4th and press the brakes?

[Pryme]

I do that on my motorcycle but I was afraid that would be harmful for the Mirage? My motorcycle has a sequential 6 speed gearbox so when i am in gear 3 .. I am able to upshift to 4, 5 and 6 without using the clutch but I was not aware we could do the same on the Mirage without causing any gear-grinding or slippage

The mirage has a synchronized transmission and as long as you dont try and ham fist it into the next gear, it can be done without a clutch. But in all honesty it's more of a party trick or emergency thing than something you would use normally.
You have to do what I said, very slowly and softly push the shifter towards the next gear and when you feel it hit a "wall" just keep slight pressure on it and when the revs fall to the right spot the shifter will push right into the next gear with no grinding

[Eggman]

One last question. In the same scenario of travelling at 40 mph, If I see light changing to red up ahead is it wise to downshift to 3rd to slow the car down a bit? Or should I just stay in 4th and press the brakes?

Just use your brakes. It'll be one less time stepping on your clutch pedal, one less time using your throwout bearing, and one less time slipping your clutch.

My 2 cents. Over time it adds up.