Auto vs Manual Transmission

[MuseChaser]

Originally Posted by c4lvinnn

Um, because cruising sometimes means (Texas highways for me specifically) going 80+ and 80 is right at 4000 RPMs? Nothing you can really do about it except change the final drive ratio and I don't care that much.

"Um," ... I'll try not to respond in a similarly snarky manner. Your point is, of course, obvious, but irrelevant to the original poster's question. He was talking about CHOOSING to "cruise" at 4K rpms, implying that there were other options. Sadly (or not), where I live cruising at 80+ garners you a LOT of negative attention by the police and endangers the lives of the rest of the folks who at least make an attempt to stay w/in the typical 55 mph and 65 mph limits of our state. If you have 80 mph highways, then of course you have no choice but to exceed 2.5K rpms. At those speeds, drag becomes more of a factor anyway so more power IS needed to maintain those speeds.. hence the lack of higher gear ratios usually available.

I stand by my point, but I'll preface it with "If you have a choice,".. just to make everyone happy.

Best,

Barry

[Elkton86er]

Wow some of these responses really make me think some of the MT crowd have inferiority complexes. Guys - its a transmission. In AT manual mode the driver still has the choice of gear and can set the desired RPM for speed.


Having said that, in "normal" auto mode the transmission wants to be in 6th gear - just like any other auto would. Around town this means your cruising at 25 mph in 6th gear at like 1100 rpm. You can override this by using the "sport" auto mode which at 25 mph will be in 3rd gear at around 2100 rpm. Or shift yourself in manual mode of course.


Personally, I have a drop-in performance intake air filter so the engine torque has enough pull to make small speed adjustments around 25 mph in 6th without forcing a downshift (this bugged the crap out of me with the stock filter). Around town cruising in normal mode is quite nice actually now. Assuming you have a flat town...

[strat61caster]

Originally Posted by Elkton86er

Personally, I have a drop-in performance intake air filter so the engine torque has enough pull to...

[c4lvinnn]

Originally Posted by MuseChaser

I stand by my point, but I'll preface it with "If you have a choice,".. just to make everyone happy.

Best,

Barry

Good, because you should preface it with that if you actually mean having a choice.

[MuseChaser]

Originally Posted by c4lvinnn

Good, because you should preface it with that if you actually mean having a choice.

It seems to me that a careful read of the original post to which I originally responded (prior to getting caught up in our current little tiff) ......

Originally Posted by ThornhillSubaruOwner

I own an Automatic BRZ.

I know people who own Manual tranny cars can rev their engines and when they drive, their RPMs are typically higher. For example, the cruising RPM is around 4k is what I hear.

In comparison, Im usually cruising at around 2.5k-3k RPM.

My question is, is it bad for the Auto transmission if I keep my RPMS high at like 4k at all times while driving?

... makes it painfully obvious that a choice was involved. Maybe I'm just supernaturally gifted with otherworldly perceptive abilities...

Granted, the OP may be operating on a few fallacious statements, i.e., that MT drivers keep their rpms higher than AT drivers as a general rule, and that MT drivers generally cruise at 4K rpm. The last part, especially, doesn't describe the way most of us MT drivers drive, but hey, that's his perception. His question is obviously regarding gear selection; there's no other possible way to "keep my RPMS high at like 4k at all times while driving." Sooo... there you have it. Please forgive me for not stating the obvious.

Have a swell day,

Barry

[c4lvinnn]

Originally Posted by MuseChaser

It seems to me that a careful read of the original post to which I originally responded (prior to getting caught up in our current little tiff) ......

....

... makes it painfully obvious that a choice was involved. Maybe I'm just supernaturally gifted with otherworldly perceptive abilities...

My interpretation was both trans can choose. No, the MT really does hit 4k at 80mph because that's the ratio. We/MT users CANT choose anything else. And AT has different ratios which lowers it to 2500 or 3000 or whatever then HE can choose to go higher due to the AT. So a one-sides choice? I guess?

But in reality, it's neither here nor there. And I don't care enough; I'm just responding to kill time on a Friday afternoon

[MuseChaser]

Originally Posted by c4lvinnn

My interpretation was both trans can choose. No, the MT really does hit 4k at 80mph because that's the ratio. We/MT users CANT choose anything else. And AT has different ratios which lowers it to 2500 or 3000 or whatever then HE can choose to go higher due to the AT. So a one-sides choice? I guess?

But in reality, it's neither here nor there. And I don't care enough; I'm just responding to kill time on a Friday afternoon

LOL.. Yeah, I'm just waiting for my wife to get home so I can finish assembling a Caesar salad and slice some bread I just made to go with.. OK.. glad it's all in fun.

Just to clarify, though.. to drive at 4k revs "at all times," meaning, not ONLY when going so fast that you have to be at that engine speed in your top gear, you'd have to shift to lower gears and REMAIN in them to keep your engine revs that high at lower speeds. Doing so is possible with either MT or AT vehicles. He was asking about the advisability of doing so. The question had nothing to do with the final gear ratios of MT vs AT. You are correct re/ the difference in ratios of 6th gear; the MT 6th is .77, while the AT 6th is .58. Both final drives are 4.10. So, yes, the rpms would be lower in the AT at the speeds you're describing. The thing is, that has no bearing on the original question.. that's all.

Enjoy your Friday,

Barry

[bababooey]

but we havent made it to 6, yet. the fun cant end.

sidenote -texas has lots 75 mph strips so youll get blown by while doing 80.

edit: op never answered the why? as posed earlier.

[ThornhillSubaruOwner]

Lool damn guys. I didn't expect to come back and see 3 pages.

Thanks for the replies, I got the answer I needed!

I just don't like how the normal mode on the auto shifts my RPMs so quick. I'd turn a corner and id get stuck trying to go up a damn hill because it shifted to 5/6th gear so quick.

I was just curious if it was BAD for the engine/transmission, not so much that I would actually keep it at 4k RPMs.

Again, thanks guys!

[bababooey]

IBTL

[guybo]

I cruise for a few miles at around 4k on my work commute. It's at a spot called "Malfunction Junction" and I like to keep my RPMs up for when some moron tries to kill me so I can scoot out of the way.

Florida drivers are THE worst.

[Tcoat]

Originally Posted by c4lvinnn

My interpretation was both trans can choose. No, the MT really does hit 4k at 80mph because that's the ratio. We/MT users CANT choose anything else. And AT has different ratios which lowers it to 2500 or 3000 or whatever then HE can choose to go higher due to the AT. So a one-sides choice? I guess?

But in reality, it's neither here nor there. And I don't care enough; I'm just responding to kill time on a Friday afternoon

Since the OP is in Ontario where the "maximum" speed is 60 if he is cruising at 80 he is in a pile of trouble. If he hits 90 and gets caught he losses his car for a few weeks and pays a $5k fine and impound fees. I had no doubt it was choice he was talking about. The presumption he was doing 80 just didn't fit.

[c4lvinnn]

Originally Posted by Tcoat

Since the OP is in Ontario where the "maximum" speed is 60 if he is cruising at 80 he is in a pile of trouble. If he hits 90 and gets caught he losses his car for a few weeks and pays a $5k fine and impound fees. I had no doubt it was choice he was talking about. The presumption he was doing 80 just didn't fit.

Forgive me when I didn't know where "Thornhill" was and the local Canadian laws

[Tcoat]

Originally Posted by c4lvinnn

Forgive me when I didn't know where "Thornhill" was and the local Canadian laws

Ahhhhh sarcasm at it's best. So the automatic assumption was an 80 mph cruise? Not a safe assumption for most places in North America.