Manual Vs Semi Automatic

[AdVERS]

I'm a former owner of an 1994 rx-7 manual transmission but i got in a serious car wreck and no longer have the car and becuase this car had a manual transmission i'm a little nervous on which transmsission to get

MY main question is which is the better transmission for say an 04-05 Infiniti G35

the 6 speed manual or the 5 speed semi automatic

[Kendahl]

They are both good. Take the one you prefer personally.

There have been some comments that the 2003 and 2004 models had a few problems which were resolved by 2005. Therefore, it might be a good idea to find a 2005 or newer.

[redhed]

you need to define what you mean by better...

[08altima35]

get what you feel comfortable with, but in my opinion the manny is better hence this thread.zerothread/306086

[AdVERS]

well heres what i'm asking does the g35 feel more sporty or sports like with a manual transmission, or does the semi aauto matic offer the same thrill. Which of the G35's will fetch more money when it's time to sell, the auto or manual.

with the partial reserch i've done isn't the G35 coupe The (6mt) model is the better model and it come with a manual transmission and brembo brakes

Vs the other models that offer the auto transmission

[telcoman]

I'm a former owner of an 1994 rx-7 manual transmission but i got in a serious car wreck and no longer have the car and becuase this car had a manual transmission i'm a little nervous on which transmsission to get

MY main question is which is the better transmission for say an 04-05 Infiniti G35

the 6 speed manual or the 5 speed semi automatic

AdVERS:

As one of the old farhts here here is my $.02

I had a 74 RX4 but that was an automatic. Being newly married the wife cajoled me into an automatic. That was the last automatic I ever bought.The wife was a little pissed when I came home with my new G two years ago but she got over it. She can pick out carpets, wallpaper, furniture, etc but when it comes to cars and large screen TV's NO F$%#ing WAY!!!

I drove the G35 automatic as a loaner and hated it. The manual is awesome. It also gets better MPG. I do not race & don't give a crap on 0 to 60 times etc. I use regular 87 octane & it performs fine for me. On drives to Florida from New Jersey a couple of times a year it is a very comfortable vehicle and after 12 hours behind the wheel no backache or leg cramps etc.In ice, snow and poor weather it handles fine using downshifting rather than having to use the brakes especially on black ice.

Many of these used vehicles may have been abused so in my opinion if I were you I would buy a piece of crap to get around until you can afford a new one.

Good luck

Telcoman

[rn79870]

I'm a former owner of an 1994 rx-7 manual transmission but i got in a serious car wreck and no longer have the car and becuase this car had a manual transmission ...

I'm a little curious about what happened. Care to share any information about how the manual transmission played a part in the wreck? (Glad you are okay)

I chose the 5AT because as cool as shifting is, to me, it is much cooler to sit there, listening to the Satellite radio, while the 5AT does the shifting. Infiniti has the best AT I've ever driven, hill holding, rev matching when going down hill (the transmission goes to the next lower gear when the brakes are used going down a steeper hill - automatically).

I recommend either the 6MT or the 5AT, either way, you'll be happy.

[joe603]

The AUTO will not last long if you go with any significant power adders. The 6MT can take more punishment. However, if you don't plan on adding FI or NO2, then your decision should be based on preference and normal driving situations. Traffic is a pain with a manual, so if you're in it a lot, consider the AUTO.

[tollboothwilley]

The AUTO will not last long if you go with any significant power adders. The 6MT can take more punishment. However, if you don't plan on adding FI or NO2, then your decision should be based on preference and normal driving situations. Traffic is a pain with a manual, so if you're in it a lot, consider the AUTO.

Agreed

With the manual transmission you will get more horseys out of the same motor, and i think you will feel the difference, being more sporty. You can manually shift with an auto, and downshift when in inclement weather too. I believe manual has better resale as well, when it has sports package.

Good luck, great choice of car!

[Tampa G35 Sedan 6MT]

GET THE MANUAL.... IF YOU LIKE TO SHIFT GET IT..... YOU WILL BE VERY PLEASED YOU DID.

I HAVE A 6MT AND WHEN IT WAS IN THE DEALERSHIP I HAD A AUTO LOANER AND I LIKED MY 6MT BETTER

IT IS THE PURE DRIVING FUN THAT MAKES THE SHIFTING IN TRAFFIC WORTH IT!

DJ

[Jacko3]

Avers:

The choice of a manual or an automatic depends on the truth you seek. Does a Robbins egg taste better than a Sparrows egg?

I am a personally a manual buff. I have never owned a car with automatic transmission. It is heresy for anyone to convince me to buy one. Just about all manual transmission cars are more reliable, lasts longer, and are sturdy than most automatic transmission cars. Just about all manuals can take more punishment than automatic trasnmissions.

One reason for this difference is the weight of the gears and the number of teeth in the gears. Manual gears are naturally heavier and have less ger teeth. Automatic transmissions have lighter gears and have more/finer gear teething. Automatics have to be light for the computer to do its work of shifting efficiently. Manuals do not have to be light because the power of your left leg will do the whole work. So, your left leg in a manual transmission must be well primed and cut-out to step on the clutch.

The ease and lightness of an auto transmission is the same reason why it does not last long. In turn, a manual transmission is as good as the clutch system you put in it. All you need to know in a manual transmission is learn to manage your clutch so that it lasts a long time. If you have a lot of money, who cares, one might as well burn the heck out of the clutch. Mind you, changing the clutch at an infinity dealership will set you back about $1,200 (parts and labor). You don't have to worry about this in an auto transmission.

The reliability factor on manual transmissions is the reason why many 18-wheelers have manuals instead of auto transmissions, while those interstate Greyhound buses actually have automatics in many cases. Manuals make it easier on the engine when those 18 wheelers have to haul heavy stuff through the mountains of the west coast. many automatic 18 wheelers will likley fail and give problems in short order under those conditions. Can't compare hauling tons of tomatos and onions across 6,000 miles and rocky mountains versus hauling 40 people across 4,000 miles on a straight road--big difference in weight and requirement.

In essence, if you want a car that will hang in there regardless of the stress you place on it, go for the manual. But it maybe uncomfortable in traffic. If you just want to be comfortable and not stress the car too much, go for the auto transmission--you will love it. But remember, don't ask for too much reliability in a auto transmission.

I have a second car with a manual transmission, with over 200,000 miles. I have done nothing to it besides changing the gear oil regularly, and replacing the clutch when needed. I dog this car out day-in day out and it actually loves to be driven hard. I doubt an auto transmission would survive my lead foot for too long.

I have always been weary of auto trannys, and would never have bought a G-35 Coupe if there was no manual transmission alternative. Manuals are fun to drive. They require more eye-hand-leg coordination, which is what excites me on the driving experience. Auto transmission makes me bored and tired, and less attentive during driving becasue it is easy. Wished they would make driving tests in manual trannys. This would weed out the wheat from the chaff very quickly, and make our roads safer.

The day auto manufacturers do away with manuals completely, that day, I shall start riding the public bus to work. But that isn't likley going to happen anytime soon.

The G-35 Coupe manual transmission is only about 15 - 25 percent of the G-35 Coupes ever made. Thus, the small production numbers and the reliability of the manual transmission of the G-35 Coupe is the reason why its resale value is higher than that of the G-35 coupe auto transmission. And I suspect as time goes on, the value fo the G-35 Coupe manual transmission will continue to appreciate relative to the date and time int he future because it will become very rare and hard to find.

Go to carmax.com and research how many G-35 Coupe autos they have for sale versus G-35 Coupe manuals they have for sale. The numbers are in parenthesis as you go through their menus.

However, you should also know that some G-35 Coupe manual transmission (2005 - 2007, Revv up engine) had some oil consumption issues. Mine was one of them. I had a new revised VQ engine put in it by infiniti for free. The engine is better and has more torque at low end speeds/RPM. And I fear the amount of torque in the new engine is actually going to cause me to buy a new clutch very soon.

Hope this helps. Just my 2 cents!

[C-Kwik]

One reason for this difference is the weight of the gears and the number of teeth in the gears. Manual gears are naturally heavier and have less ger teeth. Automatic transmissions have lighter gears and have more/finer gear teething. Automatics have to be light for the computer to do its work of shifting efficiently. Manuals do not have to be light because the power of your left leg will do the whole work. So, your left leg in a manual transmission must be well primed and cut-out to step on the clutch.

Apples and Oranges. The gear arrangement is vastly different between a standard type of auto transmission and manual transmission. Manuals use 2 sets of gears that are in a constant mesh arrangement mounted on two shafts. Automatics use a series of planetary gearsets which include a ring gear, planetary gears and a sun gear that allow for several gear ratios depending on which you lock into a static position. The weight of the gears is largely irrelevant to it being an auto transmission, but rather based on the limitations and requirements of the gears themselves. There is no reason to believe that the gears themselves are going to be a cause of failure. Even the smallish planetary gears are not much of an issue as there are several of them within a planetary gearset allowing the load to be spread out over all of the gears and also spread load over different parts of the ring and sun gears.

That said, auto trannies are usually not designed to handle significant loads above the motors they are mated to at the factory, but the limitation will likely not be in the gears themselves, but in the ability of the bands and clutches inside that actuate the different gear ratios can give out or wear quickly under heavy loads. These can be made more robust for heavy duty applications. In fact many high HP drag race cars simply upgrade these parts along with a torque converter more suited to match the power and behavior they want and get amazing results.

The use of manual gears in commercial trucks likely has more to do with the fuel efficiency than the long term reliability. Especially for the long haulers who can benefit greatly with even small gas mileage benefits.

Lastly, the weight of the gears inside the transmission has nothing to do with the clutch or the effort you place on the pedal with your left leg. All the clutch does is disconnect the output of the motor from the transmission which allows you to be able to switch gears. The effort required is entirely dependent on the spring rate of the clutch diaphram.

[Sentientbydesign]

This was already discussed ad nausea

zerothread/278374

Drive them both. See what you think. If you do a lot of driving in traffic, the auto may be better. The manual will hold it's value better IF it's taken care of. It's very easy to trash your clutch on the manual.

I personally HATED the autos on the 04 and 05 that I drove. HOWEVER, the loaner that I just drove (07? 08?) was very impressive. There was a lag in acceleration as the engine spooled up, but once it did, BAM! you were flying. Even my wife was impressed and she doesn't like to speed much.

Also, the 05 6MT coupes automatically came with the sports package which means 19" rims, the chin spoiler, and VLSD.

[Jacko3]

c-kWIK:

Granted, you provide some really intersting technical info. But i doubt that is all. if the differences are only in the ratios, then why I do routinely see cars with autos making an awful sound before they even hit 180,000 miles, meanwhile it takes forever for a manual to even apporach such a sound? I am not saying weight is everything but I do know there are marked differences in both technologies. Truckers would gladly love to drive automatic transmission 18-wheelers. Unfortunately, they rarely ever get to do so. Why?

And you mentioned that auto trannys can't handle the stress. Why? Load is a force, and that force from the engine should me matched with a corresponding weight in a transmission, which auto transmission's sorely lack. Thus, the reduced HP power of auto transmission in a G-35 coupe engine compared to the higher HP numbers in a manual transmission G-35 coupe. The lighter the gears, the easier/nimbler it is to shift using elctronics. Thus the heavier gear oil used in manual transmissions and the lighter hydraulic fluid used in auto tranniys. Did you know that the auto transmission fluid is the same type of fluid used in aircraft hydraulic systems?

If weight was not a difference between the two transmission's why do they both use two different types of fluids. Fluids are designed to address weight (load) and stress. The gear oil in manual transmission's is far heavier and more resistant to heat and break down than the auto transmission fluid. Fluids have nothing to do with gear arrangements. Though gear arrangements does play a role in the way both systems function. Of course improved gas mileage in a manual transmission is just an outcome of the whole deal.

[Sentientbydesign]

Jacko3

1. I was told by the dealership that the ratio of 6MTs to 5ATs was 1:25.

2. I have an I30 with over 275,xxx miles on the original auto transmission and it still shifts quite well and hasn't had any real servicing (maybe a couple of fluid changes).

3. Auto trannies are typically heavier than manuals.

4. I have seen probably a dozen used G coupes being sold with new transmissions. What does that say?

5. Since when does your leg shift gears? Last time I checked it was my right hand.

6. The reason those big rigs don't have autos:

You try fitting 12 or more "gear" ratios into an automatic transmission that has to handle over a 1000 ft lbs of torque.

What size torque converter will you need to pull 40+ tons

[C-Kwik]

c-kWIK:

Granted, you provide some really intersting technical info. But i doubt that is all. if the differences are only in the ratios, then why I do routinely see cars with autos making an awful sound before they even hit 180,000 miles, meanwhile it takes forever for a manual to even apporach such a sound? I am not saying weight is everything but I do know there are marked differences in both technologies. Truckers would gladly love to drive automatic transmission 18-wheelers. Unfortunately, they rarely ever get to do so. Why?

An Automatic transmission is much more complicated than a typical manual transmission. Short of gears actually breaking there will be few similarities in failures between the two. So it's doubtful you'll actually hear the same noises as the failures will likely be very different in nature.

As for automatic trucks, there are auto trannies attached to the same motors that drive the semi's. I actually drove a 24 foot Ryder truck (an International) a couple of weeks ago and it was an automatic. The problem is over a 20-25 mile drive, we used up nearly 7 gallons in fuel. Most sources seem to indicate semi's generally get about 6 mpg. As I said before, it's likely an issue of fuel efficiency for truckers to choose a manual over an automatic. Of course it's hard to compare to an average that likely includes plenty of highway miles, but if you consider even a 1 mpg difference in a vehicle that travels on a single trip across the country, the money saved can be tremendous. Especially in a vehicle that might be getting 6 mpg.

And you mentioned that auto trannys can't handle the stress. Why? Load is a force, and that force from the engine should me matched with a corresponding weight in a transmission, which auto transmission's sorely lack. Thus, the reduced HP power of auto transmission in a G-35 coupe engine compared to the higher HP numbers in a manual transmission G-35 coupe. The lighter the gears, the easier/nimbler it is to shift using elctronics. Thus the heavier gear oil used in manual transmissions and the lighter hydraulic fluid used in auto tranniys. Did you know that the auto transmission fluid is the same type of fluid used in aircraft hydraulic systems?

Actually, the only load a transmission sees is torque. HP is only a calculation based on torque. The rev-up version of the VQ35DE has 10 less lb-ft of torque than the 280 HP version. So the 280 HP VQ is putting a higher peak load on it's transmission than it's rev-up counterpart. The more likely reason the 280 HP version is still used with the auto transmission is due to emissions and fuel efficiency regulations. They have to test each motor with each transmission. The rev-up likely didn't get the results they wanted or it was determined that it wasn't worth the cost to jump through all the hoops to get an auto version of the rev-up motor on the market.

If weight was not a difference between the two transmission's why do they both use two different types of fluids. Fluids are designed to address weight (load) and stress. The gear oil in manual transmission's is far heavier and more resistant to heat and break down than the auto transmission fluid. Fluids have nothing to do with gear arrangements. Though gear arrangements does play a role in the way both systems function. Of course improved gas mileage in a manual transmission is just an outcome of the whole deal.

The fluids are vastly different in what they are asked to do. A MT's fluid is primarily a lubricant and has some natural ability to pull heat away from the gears and transfer heat out of the casing. It lubricates the gears passively as gears pick up the oil from the bottom of the case up into the gearing. It likely has some level of ability to absorb shock as poor clutchwork can put a lot of high instantaneous loads on the gears.

An AT's fluid not only lubricates, but also cleans, cools and acts as a medium to transfer power from the crankshaft of the motor to the transmission through the torque converter. Unlike the MT's method of lubrication, an AT actually pumps fluid through the transmission. In certain parts, it is pumped at very high pressures in order to transmit torque through the torque converter and hold the bands and clutches according to the gear ratio it needs to be in. It doesn't need much ability to absorb shock as the torque converter buffers any major spikes in torque.

It would seem to me that the logic you are basing some of your conclusions on is that the transmissions are similar in design. While the gear reductions and torque multiplcation factors are the same, their operation and mechanical design are vastly different. I would suggest that you read about auto trannies on howstuffworks.com. A quick look at an auto transmission specialist's site (http://www.levelten.com/products.htm) shows that there are no gear upgrades included with their upgrades. Pretty much everything but the gears are upgraded. Keep in mind these guys modify auto trannies to deal with high output V-8's.

Lastly, I'm not arguing that auto trannies are more durable overall. I only dispute your assertions as to why a MT might be more reliable than an AT.

[SVTCOBRA]

I love having an automatic!!!!! I don't manually shift it, I just enjoy driving it. I did a few times, but didn't like the delay. Maybe I need the grounding kit. (always owned a stick)Still have a 5mt cobra.

[C-Kwik]

The Titan I drive now is the only automatic equipped vehicle I've ever owned. It's not terrible as it's a truck, but I still miss being in the gear I want when I want. Even manually shifting it, it still never feels the same.

However, I think in the next 10 years, we may start seeing more common use of dual clutch systems or perhaps see more of what Lexus is going to do with the upcoming IS-F. The IS-F will be using an automatic transmission but the torque converter will remain locked at all times except when starting out in 1st gear. That translates to ultra fast shifting, without the drivetrain losses and engine braking will be more direct. Both dual clutch systems and the IS-F will be able to shift manually or drive like any other automatic.

[redhed]

hey c-kwik,

just wondering if that truck you drove actually had an automated mechanical trans vs an automatic? seems to me that most of the heavy duty applications i've seen forego a true automatic with it's problematic torque converter and instead employ an AMT.

[Jacko3]

C-Kwik:

Nice technical info! I am still not convinced!

[ACoupe]

Hey SVT, what's a grounding kit?

[Sentientbydesign]

So do I need to post another thread asking G owners how long they've their original transmissions lasted?

I'll bet money that the ratio of manuals to autos that had to be replaced was atleast 3:1.

[zozoka1212]

I love manual trani however I would not buy it for daily drive. I guess I've grown up. I am thinking to buy a 350z or something similar to that for weekend drive. That would be manual trani.

I am happy with the semi for a DD. If you want some fun you can throw it in semi and give her or just drive it in auto when you are in traffic as Joe said it.

I really hate manual in traffic. Drives me nuts.

zozo

I guess what I tried to say is up to you what you like. Ther is a little more power in the manual if you looking at the 03-04 models.

[C-Kwik]

hey c-kwik,

just wondering if that truck you drove actually had an automated mechanical trans vs an automatic? seems to me that most of the heavy duty applications i've seen forego a true automatic with it's problematic torque converter and instead employ an AMT.

It was some sort of International. 24 foot box truck. It was definitely an automatic. The engine braking was too light to be any kind of manual.

[redhed]

i'd second that!

with the automatic trans there are so many "protective" electronics going on that it would be harder to destroy it vs the manual. can't drop the clutch in an automatic at 5k rpms!

[Sentientbydesign]

i'd second that!

with the automatic trans there are so many "protective" electronics going on that it would be harder to destroy it vs the manual. can't drop the clutch in an automatic at 5k rpms!

I have a friend who killed his Celica doing that. I think that was his first auto lol.

[Tampa G35 Sedan 6MT]

So do I need to post another thread asking G owners how long they've their original transmissions lasted?

I'll bet money that the ratio of manuals to autos that had to be replaced was atleast 3:1.

39k miles on my G and I am on clutch #3 and Trans #2........

The two clutches and the trans were replaced under warranty!

It was due to a bad slave cylinder that is the reson for the first clutch.

Then they fixed that and they never quite fixed it right.... Something about a syncronization between the slave cylinder and the clutch.... cost them a new slave cylinder, clutch, and transmission.

I got a new transmission due to infiniti tech error!

But still, My auto lexus never had a problem!

I drove a is 300 2years and an is 350 lexus 1 year and never had any problems on the transmissions.

They were both autos and IMO much better autos than the Infiniti auto that is in the G35.

The 300 had a 5 speed and the 350 a 6 speed and you never found them between gears or in the wrong gear. Never did it jerk into a gear or take to long to shift.

The infiniti autos are like that... They are not the best IMO in the business for autos...

Bottom LineIF you want an auto get a Lexus! IF you want a Fun to Drive 6 Speed Car.... Get the INFINITI!

Old trucks and cars... The Manuals lasted much longer becasue lack of computers to make the autos last longer...

Now it is reversed.. The manuals are lacking the technology... The autos are completly computerized so they are lasting longer!..

But i still see the technology and the amount of companies producing manuals fading away. I don't think it will be too long before you see cars that are all auto.

For the Record!The IS F is the best Auto in the Business

DJ

[Rivalry]

I am amazed at the information C-Kwik contains!

Ninjas4life!