What RPM @ 70MPH etc...

Post by **Wyld Bill** » Wed Nov 29, 2006 7:58 am

I'm trying to figure out why the Suzuki SX4 gets such poor gas milage (compared to a Versa). Anyone know what they are running for RPMs at 65MPH & 70MPH?Anyone know what the axle gear ratio & 5th gear gear ratios are? How about the tires diameter?

I'm going to post on the SX4 forum & compare the results to see if my suspision is right,....that the 6th gear of the Versa might help it to get better gas milage or,...is the gearing from the engine output to the ground in 6th close to 5th in the SX4 & it's the AWD that's making it get bad MPG?So is 6th like O.D. or just for the "curb appeal".

Post by **Jemdawg** » Wed Nov 29, 2006 9:50 am

The 6th gear is for economy, it's the gear you'd want to use to drop your RPMs down to a more optimal range on the highway or even in the city sometimes. Usually, if a tranny is advertised as a 6 speed manual, it has 6 gears and an overdrive gear. I believe, for the most part, 4AT would mean that there are 3 gears and an overdrive gear. Normally you cannot manually shift into overdrive, as the tranny does it for you, so that would mean that the 6 speed is truly 6 speeds plus an overdrive gear.

Gas milage is determined by many many many factors. It's hard to do a comparison of why one car has better gas milage between different cars. When you compare two of the same cars, it's much easier, because they were designed the same way so you only really have to compare driving habits, weight differences, mods, etc. To compare your Suzuki to the V would involve more than just that, you'd need to compare the curb weights, the engines, the torque outputs, the gear ratios, etc.

Post by **Ever Victorious** » Wed Nov 29, 2006 11:54 am

Overdrive is defined as a gear with a ratio lower than 1. Both 5th and 6th gears in a Versa are "overdrive".

Overdrives in manual transmissions are part of the counted gears.

Overdrives in automatics are usually electronic or "fourth" gears... so a 3AT w/OD is basically the same thing as out 4AT on the Versa. Disabling O/D on MOST automatic transmissions (except CVTs) makes it so the car cannot shift into 4th.

Post by **Wyld Bill** » Wed Nov 29, 2006 12:13 pm

So

Ever Victorious wrote:Overdrive is defined as a gear with a ratio lower than 1. Both 5th and 6th gears in a Versa are "overdrive".

Overdrives in manual transmissions are part of the counted gears.

Overdrives in automatics are usually electronic or "fourth" gears... so a 3AT w/OD is basically the same thing as out 4AT on the Versa. Disabling O/D on MOST automatic transmissions (except CVTs) makes it so the car cannot shift into 4th.

what are they then?? The ratios for 5th & 6th in a Versa??

Post by **Jemdawg** » Wed Nov 29, 2006 12:43 pm

I see, I see, I'm not as savvy on standard trannys as I am with automatics.

Post by **motoguy128** » Wed Nov 29, 2006 4:31 pm

I usually consider overdrive any gear that is taller than required to reach either the drag limited top speed or redline. with a wide variety or final drive ratios, just having 5th or 6th gear less than 1.0 is a little misleading.

Post by **Ever Victorious** » Wed Nov 29, 2006 4:47 pm

Wyld Bill wrote:So what are they then?? The ratios for 5th & 6th in a Versa??

My owner's guide is sitting in my car. Still at the body shop. Someone else will have to look this up and answer for me.

Post by **Nolalove06** » Wed Nov 29, 2006 5:16 pm

sooo...like in 6th gear...my RPMS seem kinda high...i forgot what they are, but at 80 MPH i think it was 3500 is this the norm?

Post by **chano129** » Fri Dec 01, 2006 11:59 am

EV is correct usually 5th and 6th or below 1 in newer cars. The cvt maxium is .4 and the 6th in the manual also .4 and the 5th is around .7. The older tranny and manual shift had closer ratios but since new design that let trnnies weight being less, they now have wider gear ratios for fuel economy.there is also a lock up torque converter which assist the vehicle in the 5th and 6th speeds.that is for the VERSA for suzuki you would have to do some reading. Noloalove06 that rpm is normal for any car, the faster you go in high speed, the rpm willl also go up, because the car has to be put in more fuel to match the ratio of air entering the engine, because when you press the accelarator it opens the throttle wider allowing more air inside.At this speed you will get bad milage, unless you do mind getting bad milage, around 65 70 mph or 120 110 kmh should be fine.

Post by **chano129** » Fri Dec 01, 2006 12:33 pm

A four speed AT (4AT) has five set gear ratio and a six speed has seven set gear ratio and so on.It is called a 4speed tranny because it only shift four times.It is similiar to a manual, if you are going to move a manual you are in first gear or low gear, but on a AT ,you put the shifter in D, the tranny is at it set gear ratio at this instant, you shift out of first gear four time (4x)to reach fifth and the same the tranny,it shift four times automatically.But all trannies are different because of the ratio they are made with, some tranny ratio are wider than some.

Post by **chano129** » Fri Dec 01, 2006 12:56 pm

i will give a little more details,because the speed of the car increases, the engine speed will also increases,because the car engine has to do more revolution to gain the required speed.80 mph is the speed the car travels and 3500 means the engine is doing 3500 revolutions per min. to achieve that speed.But the car needs more gas and air to obtain that speed in each cylinder.The air to gas ratio is 9.9:1 for the Versa when throttle at normal temperature about 800 rpm, so if you go to 1600 rpm the ratio will double but is still equal to 9.9:1 but more gas and fuel entering the cylinders.

Post by **versabundus** » Fri Dec 01, 2006 1:15 pm

There are a multitude of factors affecting MPG. Driveability, weight, , aerodynamics,mechanical drag, etc.I personally don't like how tall 6th is in the Versa. It makes it more driveable on the highway, but I think it does so at the cost of mileage. I certainly wouldn't mind downshifting to accelerate. But there are those that have differing opinions. The manufacturers have to weigh their choices. Usually the most dedicated designs fare poorly. Look up the MPG on the european version of the Versa. I doubt the US version would fly there. As an interesting side note, Suzuki is the best selling car in Japan. Mostly Kei Jidousha, or Keicars. Tiny little things. Anyway, getting back to the original thought, I would say its the combination of 143 hp., AWD , Tire size , Tallness of greenhouse, ground clearance, and driveability.
Modified by versabundus at 3:38 PM 12/1/2006

Post by **msb0b** » Fri Dec 01, 2006 3:21 pm

This site has gear ratios listed on the specs page. The 6th gear in 6MT may seem very short but don't forget to factor in the different final drive ratios. At the highest ratio, 6MT revs 36% higher than the CVT and 12% higher than the 4AT travelling at the same speed.

Compared to my previous car, a VW GTI, the Versa's 6th gear is shorter than GTI's 5th. That is, Versa revs higher at almost 3500 rpm and GTI at 3000 rpm at 75 mph. The reason being GTI's engine can produce 50% more torque to overcome the mechanical disadvantage.

chano129 wrote:there is also a lock up torque converter which assist the vehicle in the 5th and 6th speeds.

There is no torque converter in a manual transmission. Manual transmission uses clutch to transfer power from engine to wheel.

chano129 wrote:A four speed AT (4AT) has five set gear ratio and a six speed has seven set gear ratio and so on.It is called a 4speed tranny because it only shift four times.

4AT has 5 gear ratios--4 forward and 1 reverse. It takes 3 shifts to get to top gear. It goes 1-shift-2-shift-3-shift-4.

Post by **motoguy128** » Fri Dec 01, 2006 7:27 pm

If 6th gear was taller, it wouldn't be as useful in the city and less flexible. This is a international gearbox. The shorter 6th gear means that you can carry 4 adults and still hold 6th gear up hills at 45 mph without downshifting. THe negineers may also have been limited on the total range available while maintianing it's compact size. They may have had to choose between a taller 6th gear or a shorter 1st gear.

Like I've mentioned on other posts, this drivetrain is also used on larger heavier vehicles. Nissan & Renault had to compromise on the gearing to get one drivetrain for all applications without changing the final drive ratio.

Post by **chano129** » Sat Dec 02, 2006 4:56 am

thank you, i leave out some parts i should have said the versa cvt and 4AT has a lock up torque converter,donot be quick to judge anyone can make mistakes.

Post by **chano129** » Sat Dec 02, 2006 5:12 am

And i beg to differ on the 4AT tranny, it is 5 gear ratios and it is five forward and not four.when you put it in D it ids already in one gear or 1 forward, then when you easy up of the brake and accelerate it is 1stshift 2ndshift 3rdshift 4thshift which is O/D.I think you are confusing it with the previous 3speed AT/tranny. And these ratios are set.If you donot believe, check in a HAYNES REPAIR MANUAL.transmissions number RL3F01A 3speed and RL4F03A or V 4speed.VW and nissans are different keep that in mind.

Post by **chano129** » Sat Dec 02, 2006 5:21 am

Motoguy that post you just did it is awesome, you hit the nail head,that is nissan and renault objective with the cvt and the 6 speed manual, to keep the gear as long as possible, that is why the CVT has a little hickup when you ask it for more power. And as i say all manufacture are a little different.

Post by **chano129** » Sat Dec 02, 2006 5:51 am

You cannot just compare a european Versa to an American because you use american gallons and the europeans imperial gallons,unless you are going to convert measurements.And further more they uses metric measurements.But i must admit the 1800cc in Japan give better mpg.probably because of the air.

Post by **chano129** » Sat Dec 02, 2006 7:09 am

The manual mode i was talking was a CVT and here is an offical spec from nissan.http://www.nissan-global.com/E...a.pdfN.B. the 4AT has four set gear ratio, which it shift only three times, but it also has an over drive,which is button operated to disable or enable it,to make it shift four times,but it was not mention in the specs,but the over drive does has a ratio , but it is a gear that has a specific gear ratio, that is how you get five set gear ratios.

Post by **msb0b** » Sat Dec 02, 2006 7:23 am

I agree that having short gears makes it useful for city driving. I wish that the 6th gear is a little taller so the car can cruise a a little lower rpm at highway speed. It seems like the 6th is optimized for driving at 60 to 65 mph. But around here, the interstates' speed limit is 75 mph, and Versa's engine has to rev to 3500 to 4000 rpm to keep up with traffic flow. Noise, vibration and harshness (NVH) can also be an issue when traveling at this speed for hours at a time.

chano129 wrote:And i beg to differ on the 4AT tranny, it is 5 gear ratios and it is five forward and not four.

The facts are disagreeing with your claims here. If the 4AT has 5 forward ratios, then all 5 ratios would be listed on this site's specification page. Furthermore, Nissan would market such equipped car as a 5AT, 5 speed automatic, not 4AT.

Post by **electech** » Sat Dec 02, 2006 9:26 am

I don't know if anyone answered the rpm question or not. I own the CVT but have driven both at 70 mph. On my CVT, at 70 mph, it is turning 2400 rpm. The one with the 6 speed I drove was turning 3000 rpm at the same speed.

Post by **chano129** » Sat Dec 02, 2006 9:57 am

It is very simple, why don't you just drive a sentra if you connot get a versa with a 4AT/tranny, make sure the o/d is activated and I will bet you any money it shifts four times.Then disable it and it only shift three.I actually see one that was pull a part that is how I know.The four gear ratio nissan mention is the four planetary gears but it did not mention the high speed gear which is the over drive which can be controlled by you. And if you are not convince here is a lay out diagramhttp://www.shinseiauto.com/jap...4.pdf

Post by **chano129** » Sat Dec 02, 2006 10:16 am

http://www.nissannews.com/niss...shtml

If you look at the specs there is a difference in gear ratio between the 4AT 6MT and the CVT.There is also other factors like the engine.

Post by **Ever Victorious** » Sat Dec 02, 2006 11:47 am

Chano -

This is the second time I have had to ask you this.

If you are going to respond to four people, please consolidate your response in ONE message, as opposed to creating four individual replies. Also, please use the quote button every now and then so we can follow who (and what thought) you are replying to.

If you don't know how to do this, please let me know and I would be glad to enlighten you.

Post by **motoguy128** » Sat Dec 02, 2006 12:21 pm

Chano,

You might want to read a few things more closely. I think you might be mixing some things up in translation. The fuel/air ratio in internal combustion engines is NOT 9.9:1. It is typically 14.7:1, or higher for improved emissions and economy. 9.9:1 is the compression ratio of the engine. This is a mechanical measurement representing the volume of the combustion chamber when the piston is at the top of the stroke compared to the bottom of hte stroke. The actual volume of air inside the cylinder will depend on the level of vacuum in the manifold which is affected by restrictions such as the air filter, ducting and of course the throttle body and intake valves. A higher compression ratio has the advantage of allowing better true effeciency in the motor because the combustion is allowed ot expand by a greater percentage on each power stroke. ON the downside, higher compression engines genrally do not perform as well at lower RPM's and depending on the valve and ignition timing and chamber/piston design, may require higher octane fuel.

I'm not flaming... just don't want anyone to get the wrong idea.

The power output of hte motor is varied by the total volume of fuel allowed into the cylinder. Higher RPM's while producing the same net power output have the disadvantage of increased internal mechanical and pneumatic friction losses as the enigne operating less effeciently because it's effectively too large and the mixture is not compressed as well.

Post by **versabundus** » Sat Dec 02, 2006 2:51 pm

chano129 wrote:You cannot just compare a european Versa to an American because you use american gallons and the europeans imperial gallons,unless you are going to convert measurements.And further more they uses metric measurements.But i must admit the 1800cc in Japan give better mpg.probably because of the air.

If you get the conversion between liters and gals. you certainly can compare.Most Euro countries use liters, not imperial gallons.

What RPM @ 70MPH etc...

What RPM @ 70MPH etc...

Re: What RPM @ 70MPH etc... (Wyld Bill)

Re: What RPM @ 70MPH etc... (Jemdawg)

Re: What RPM @ 70MPH etc... (Ever Victorious)

Re: What RPM @ 70MPH etc... (Ever Victorious)

Re: What RPM @ 70MPH etc... (Jemdawg)

Re: What RPM @ 70MPH etc... (Wyld Bill)

Re: What RPM @ 70MPH etc... (Ever Victorious)

Re: What RPM @ 70MPH etc... (Jemdawg)

Re: What RPM @ 70MPH etc... (Nolalove06)

Re: What RPM @ 70MPH etc... (Wyld Bill)

Re: (chano129)

Re: (msb0b)

Re: (msb0b)

Re: (msb0b)

Re: (motoguy128)

Re: What RPM @ 70MPH etc... (versabundus)

Re: (motoguy128)

Re: What RPM @ 70MPH etc... (Wyld Bill)

Re: (msb0b)

Re: What RPM @ 70MPH etc... (electech)

Re: What RPM @ 70MPH etc... (chano129)

Re: What RPM @ 70MPH etc... (Ever Victorious)

Re: What RPM @ 70MPH etc... (chano129)

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