Rev matching: opinions?

[peoples1234]

Brakes are to slow a car down, not the clutch.
The purpose of rev matching is to help smooth out transitions between gears keeping the chassis stabilized, not to decelerate aggressively.

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[Silver Bullitt]

What are you on about? It only rev matches when you start to enter the gate. Just pushing in the clutch doesn't cause it to rev matches, nor pushing in the clutch and going into neutral, or pushing in the clutch and releasing it again without changing gears. Beyond that, subject to your own opinion of when one should rev match, it does work perfectly. It blips the throttle and holds that speed in case you're being super lazy and taking forever to release the clutch. When it doesn't work perfectly is when it sometimes doesn't want to work at all, and this is jarring when you're not used to it happening. The pcm does seem to give a slight rev when releasing the clutch, in first gear, if this is what you're referring to. This isn't rev matching, though. It's this kind of nifty thing that lets you ease off the clutch without having to touch the gas pedal. It makes parking in my garage and stop and go traffic really easy to deal with. Honestly, the pcm's subtle management of the engine speed has made this the easiest, manual transmission, daily commuter I've ever driven.



As another lifelong stick driver, I also love it. I even have an aftermarket exhaust. I was a little self conscious of it at first but I quickly got over it. It's saving a lot of wear on your transmission and drivetrain. I daily my car so any help in prolonging it's mechanical components is fine in my book. My car's longevity means more to me than someone's opinion of me that I'll most likely never meet. Anyone who has inquired about "why" seemed to think the feature was really cool, when I explained it. I can't say I've ever relied on engine braking much, though, so if it's engrained into your driving technique then I guess I can see it taking some getting used to. I disabled hill assist for a similar reason.

I will qualify my opinion as I haven't driven a Mustang with the feature. My experience was in a Camaro. It's still not a feature I would prefer over just doing it yourself when and only when you want it to.

 

[Michael_vroomvroom]

For someone who goes by the name Michael_vroomvroom, you seem overly self-conscious about the car's engine sound.
It sounds great! Revel in it, I say.

Haha. I love the sound my Mustang V8 makes, I agree it sounds great. I also love the sound of my Fireblade motorbike when I rev it, but I'm thinking that if I find it annoying to listen to some clown reving his engine as I'm walking around in the city or having a cup of coffee, it's gotta be even more annoying for the other 99% that have zero interest in bikes or cars. So I try to be polite, even if it's towards someone I don't know and will never meet. :-)

Outside the city there's not much reason to care, but with stop and go traffic in the city and shifting between first and second quite a bit, I think it's not too good. E.g., when I'm snailing along in second gear in the city, and have to slow down because traffic ahead is slowing down, I usually downshift, both to get in a more suitable gear and to slow down a bit for the new pace. The Mustang's rev match logic revs the engine when I downshift while I still have the clutch firmly disengaged, which makes me feel like someone who doesn't yet know how to change gears as the engine revs up. My daughter thinks it sounds really cool though. ;-)

 

[Clump]

I'm really happy with it. So far it works really well. If I'm coming to a stop and don't want the blips I just hold the clutch in and shift to 1st after it's stopped.

I rarely tried to manually rev match with previous cars. When my friend, who makes a habit of manually rev matching drove my car the auto blip really annoyed him. I guess that's why it can be turned off.

 

[atomicpunk]

Coming from an S-197 with a manual where blipping the throttle to downshift either did nothing or over revved - I'm loving the rev matching.

 

[NoVaGT]

Assuming you call "perfectly every time" when you push in the clutch to stop at a light or stop sign. I'd hardly call it perfect. There are times when you are slowing down there's no need for a rev match. That was the main thing I found really annoying.

Mine works perfectly every time. No issues. I don't use it coming to a stop, the cars out of gear at that point.

 

[Zrussian13]

I could've turned it off and taken the time to get a feel for what engine speeds I need to be at around for which gears at what speeds. But it came with it so I skipped that part of learning a new manual tranny.

I'd say it's a qualified yes on making one sound like a douche. Yes, cuz it revs your engine even when you don't want it to. But not any more than the loudness of these cars accelerating hard. So I look like a douche on the roads no matter what. (Since I didn't buy this to always just drive it like a granny.)

The only other drawback I've noticed is there's a little delay. If the light's turning yellow and I want a burst of power to enter on yellow, there's a thunk and jerk as I'm not waiting for it to do its thing.

Interesting you feel a delay in yours. Mine seems very quick and responsive with the rev match every time. I do agree on the looking like a douche but I'm like you. Drive it hard all day long so people probably already think I'm a douche. If the only knew how fun these cars are... Never a boring ride!

 

[3star2nr]

Just got my 2020 Mustang. My very first time I've bought a car I actually want, rather than just the cheapest that "would do", so everything's great of course, but I wonder what other manual transmission guys think of the rev matching feature. The first few hours (long drive home) I thought it seemed interesting and somewhat nice, but now I'm starting to change my opinion. Perhaps I'm using it wrong?

I'm used to pretty aggressive downshifting on my motorbike (Honda's "super sport" fireblade model. Something like the motorbike equivalent of the "super car" term for those who don't care about bikes) while on the road. No automatic rev matching there, at least not on my old model, so depending on whether I'm downshifting to slow down as I'm getting off the highway, or downshifting to accelerate, I'll either blip the throttle by a little or by a lot.

I'm still babysitting my Mustang and keeping the rpm's low until I've reached 1600km/1000 miles, so the only downshifts where I feel the rev matching kicking in are when I want to slow down. E.g., downshifting from second gear to first gear as traffic is slowing. This however creates a rather impolite "vrooom" sound in the milliseconds between me disengaging the clutch and downshifting, and me engaging the clutch again.

While the clutch is disengaged as I'm downshifting, the computer obviously does a rev match in preparation for me re-engaging the clutch in the lower gear, and increases rpm by some five hundred or a thousand (at least for now, as I'm still breaking her in), which everyone around the car can hear quite well. This makes me feel a bit like those clowns on motorbikes that like to rev their engines for no good reason in the city center, annoying everyone around.

Basically it feels like this feature is something that would work well for downshifting to accelerate (which I have not tried yet), but I'm more dubious about the usability of it regarding downshifting for slowing down. On the bike I usually do some limited rev matching while downshifting to slowdown, but to a much lesser extent than the Mustang's computer, and I do the matching while releasing the clutch, so the sound effect is much less pronounced.

Being a Mustang newbie (and a newbie regarding anything but "whatever is cheapest" cars in general) I'm interested in hearing more knowledgeable peoples opinion on this feature. I guess it reduces wear on the clutch a little bit, , but I don't like the free spinning increase in revs as it makes me feel as one of the aforementioned idiots on bikes.

Well it depends... Do you care more about protecting your driveline and getting the smoothest possible downshift or do you care what the idiot in the dodge neon who cant afford your car thinks...

My car is a 2016 PP I rev match it every single day i dont even think about it, it's just how I drive. I've even rev matched a pickup truck. Lol

Its about protecting the driveline and smoothly transfering the weight entering the corner so the car doesnt get upset under braking.

You can just not downshift and go to neutral, but this car isnt for the politically correct. So let it sing, bald eagles, freedom, America all that stuff

 

[3star2nr]

Brakes are to slow a car down, not the clutch.
The purpose of rev matching is to help smooth out transitions between gears keeping the chassis stabilized, not to decelerate aggressively.

exactly. When you do it right you dont feel anything. Thats the entire point of a rev matched downshift...

If it feels "aggressive" you're revving too high and lunging the car, thats tearing up your transmission, u joints, CV joints and synchro, forks, bearings etc... Not to mention upsetting the tires traction. U may not see the danger of that on a sunny commute to Wal-Mart, but do it in the rain on a cambered surface and thats a great way to snap oversteer into a guardrail... Fortunately for you the s550 is set up so well it will forgive even the worst drivers

 

[shogun32]

When I'm carving my back roads I tend to turn it on - but since I ride 2-wheelers, I'm typically already blipping the throttle manually. The only times it really comes into play is if I'm hard on the brakes and trying to also negotiate a very tight turn and shift all at the same time.
You're supposed to use the brakes to stop, not the trans. Sure I get a small burble when rolling to a stop and shift into first, but it's quite modest.

When driving the Camaro I don't mind the auto-blip as much as I detest the gratuitous crackle and pops.

 

[3star2nr]

Coming from an S-197 with a manual where blipping the throttle to downshift either did nothing or over revved - I'm loving the rev matching.

You can do it just fine in an s197. Just takes patience and practice

 

[cib24]

I freaking love it. I didn't think I would but it makes driving so much smoother now all the time. I also like it because I find the stock pedal placement too far apart for me to heel and toe (or even toe and toe) due to such long narrow feet.

I also see it as a benefit to the transmission as it take some stress off the clutch and gearbox, and the fact that it's auto blipping for me on downshifts means I am downshifting far more often when coming to a stop, and that means I am using more engine braking which is good for fuel saving (not that this really matters to be honest) and is also helpful to the rest of the drivetrain. I'm not worried about engine wear or whatever was posted earlier. Ford builds like over 500,000 of these Coyote engines per year and they tend to run forever minus some of the issues only a handful of people have experienced.

 

[Norm Peterson]

Sorry for not being specific, but yeah, I do blip the throttle a little or a lot. Blip it enough to not lose traction, blowing the transmission, or anything stupid happening, but since my intent is to slow down, I don't want to rev match it like the Mustang does.

I guess the feature is useful for that; if traffic has slowed down a bit, e.g. from 70 to 50 and you're starting to feel like you're in the wrong gear. Easy to shift down a gear and let the rev matching take care of things so you can continue driving at 50 in the lower gear. It seems perfect for that, but less so for downshifting to slow down, unless you like to make a lot of noise while doing it.

What you've found rev match to be good at is precisely what it is supposed to be good at, and the only thing it's supposed to be useful for.

Intentionally chasing strong deceleration due to engine compression effects is not even why you should be downshifting. Short of experiencing partial or complete loss of service braking, anyway.

As others have said, that's what the service brakes are for. Downshifting while decelerating is something you do either (1) in anticipation of upcoming acceleration, or (2) to allow the engine to remain in a more comfortable rpm range while you're scrubbing speed off with the brakes (you're basically just keeping the engine from lugging as you decelerate, while still keeping the engine connected to the drive wheels). Under the latter scenario (#2), any deceleration that you're getting from engine compression while intentionally slowing down is strictly incidental, and should never be taken as the primary (or only) reason to be downshifting under such situations. Subject to the emergency exception above.

FWIW, I do downshift under situations that fall under #2 above. But I rarely find myself downshifting below 3rd gear, and never into 1st unless I'm within about 3 mph of coming to a full stop. Yeah, there is a bit of anticipation about what's happening ahead of me going on, but you're supposed to be doing that anyway.

Downshifting to accelerate I guess the rev matching won't be felt much as you'd manually increase the rpm to more than the rev matching computer is doing anyway.

Done 'perfectly', you shouldn't feel anything at all. No lurch forward (because you didn't kick the revs up high enough or your timing was off and you let the revs decay too far before your left foot got its part done), and no rearward head-toss (you kicked the revs up too high and/or your timing was off the other way and you let the clutch out too soon). I'd like to believe that this is a skill that comes with practice. Make that proper practice, where the measure of your progress is in how little you feel anything when you downshift.

This also translates directly to minimizing chassis upsets caused by power delivery errors. Not just minimized below what your skill set can manage, but minimal in absolute terms.

Think this feature is not so useful for me as it's currently implemented then.

It's intended to assist downshifting when it's being done for the right reasons. You need to fix you here.

No flame intended, but I just can't avoid being bluntly spoken about this. I'd score your described use of downshifting under #2 as about a 'D', and I'm feeling a bit generous this morning. There's no reason you couldn't bring that up to at least a 'B-' if you're willing to put some effort into it.


Norm

 

[Norm Peterson]

Coming from an S-197 with a manual where blipping the throttle to downshift either did nothing or over revved - I'm loving the rev matching.

All you needed was more practice to get your timing (and approximate amounts of blipping) down. Those things aren't nearly as difficult to learn as you think.


Norm

 

[13GetThere]

Hey, I like rev matching. It lets me know when I down shifted when I meant to up shift before I let the clutch out. Still relearning the manual, and the rev match helps, but I can see where it would be an annoyance if you were already used to a manual.

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