CVT and Mazda, Engineering Explained

[PimTac]

Originally Posted by Ws6
Cvt is a great stopgap idea until electric goes mainstream (area under the curve), it just isnt implemented reliably.




This is the BITOG opinion. Meanwhile, millions upon millions of CVT vehicles roam the earth every day with no problems.

 

[bbhero]

Originally Posted by PimTac
Originally Posted by Ws6
Cvt is a great stopgap idea until electric goes mainstream (area under the curve), it just isnt implemented reliably.




This is the BITOG opinion. Meanwhile, millions upon millions of CVT vehicles roam the earth every day with no problems.



^^^^^^^^^

Fair amount of truth here...

I have 272,000 miles on my CVT 08....


Key parts of its problems have been...

#1 World champions putting the wrong fluid into the one they have...

#2 Improper ECM settings from the factory which have caused lots of issues... Aka the transmission always searching for highest gear ratio for maximum fuel economy... Not good at all. Add to this... High gear ratio and high load... terrible combination.

#3 These transmissions need a bigger motor... 1.6L 2.0L, and even 2.5L motors are not a good match for a CVT... The 3.5s have actually performed much better with a CVT vs the smaller motors....

 

[edyvw]

Originally Posted by bbhero
Originally Posted by PimTac
Originally Posted by Ws6
Cvt is a great stopgap idea until electric goes mainstream (area under the curve), it just isnt implemented reliably.




This is the BITOG opinion. Meanwhile, millions upon millions of CVT vehicles roam the earth every day with no problems.



^^^^^^^^^

Fair amount of truth here...

I have 272,000 miles on my CVT 08....


Key parts of its problems have been...

#1 World champions putting the wrong fluid into the one they have...

#2 Improper ECM settings from the factory which have caused lots of issues... Aka the transmission always searching for highest gear ratio for maximum fuel economy... Not good at all. Add to this... High gear ratio and high load... terrible combination.

#3 These transmissions need a bigger motor... 1.6L 2.0L, and even 2.5L motors are not a good match for a CVT... The 3.5s have actually performed much better with a CVT vs the smaller motors....

I would say Nissan hit better with CVT made for 3.5. Generally CVT and higher torque do not go well together.
Audi started using CVT developed together with LuK in 1999, and they had A LOT of teething issues in application with diesel engines.

 

[bbhero]

I think the 3.5 motor was/is a perfect fit for the CVT...

And I agree... A CVT paired with a high output motor of say 400 hp plus... May well not be a good idea.

Just like a 1.6 etc are not a good pair with a CVT...

 

[edyvw]

Originally Posted by bbhero
I think the 3.5 motor was/is a perfect fit for the CVT...

And I agree... A CVT paired with a high output motor of say 400 hp plus... May well not be a good idea.

Just like a 1.6 etc are not a good pair with a CVT...

Audi had issues on smaller turbo diesel, particularly 2.5 V6 TDI engines (that never made to the US.), though by European standards that is big engine. That engine itself is one of the worst diesels ever made, period, but transmission was actually worse.
As for 3.5 Nissan, I highly doubt it is same as CVT in smaller engines (I never ventured into CVT technology that much as I hate them). So Nissan hit it with CVT for that engine. But, we will see how will it go with turbo engines. That is where problems might come out as turbo engines are becoming more present. On other hand, things will be resolved, weak links etc.

 

[bbhero]

I have to look into it...Whether or not it is the same CVT in the 2.5 vs 3.5s.. May well not be but it could possibly be...But either which way... A small motor is just not a good combo with a CVT...

I agree with you that it will be interesting to see what happens with turbo boosted motors and CVTs. I'd rather just have a 3.5 NA motor vs a small high strung GDI turbo motor.

 

[Ws6]

Originally Posted by bbhero
I have to look into it...Whether or not it is the same CVT in the 2.5 vs 3.5s.. May well not be but it could possibly be...But either which way... A small motor is just not a good combo with a CVT...

I agree with you that it will be interesting to see what happens with turbo boosted motors and CVTs. I'd rather just have a 3.5 NA motor vs a small high strung GDI turbo motor.


3.5NA motors are far more high-strung than 2-2.5L GDI motors. [censored], my last 3.7 V6 only made 270# of torque and 332hp and revved to 7500rpm. Max torque was at something like 3K rpm (although it was flat as a table-top), and max HP didn't happen until well over 7K. In contrast, my turbo 4-banger makes 310# torque at 2000rpm, and max horsepower (250) at around 5000rpm. It's far and away not the most powerful of the turbo 4-bangers out there, either, but it works a lot less than V6 or I6 in the same application.

 

[PimTac]

Originally Posted by bbhero
I have to look into it...Whether or not it is the same CVT in the 2.5 vs 3.5s.. May well not be but it could possibly be...But either which way... A small motor is just not a good combo with a CVT...

I agree with you that it will be interesting to see what happens with turbo boosted motors and CVTs. I'd rather just have a 3.5 NA motor vs a small high strung GDI turbo motor.





Im guessing it's a Jatco CVT8 which is their latest model. There are a couple of variations.

https://www.jatco.co.jp/english/products/cvt8.html


As for CVTs in general, the issue is really a personal one for the owner. Many are used to a shift pattern which a CVT doesn't have. Also, my guess is that a lot of buyers think these are just automatics and don't know the difference.

Once a driver adapts to the CVT all is good. Granted, the earlier models had their issues. The more recent versions are vastly improved.

 

[edyvw]

Originally Posted by PimTac
Originally Posted by bbhero
I have to look into it...Whether or not it is the same CVT in the 2.5 vs 3.5s.. May well not be but it could possibly be...But either which way... A small motor is just not a good combo with a CVT...

I agree with you that it will be interesting to see what happens with turbo boosted motors and CVTs. I'd rather just have a 3.5 NA motor vs a small high strung GDI turbo motor.





Im guessing it's a Jatco CVT8 which is their latest model. There are a couple of variations.

https://www.jatco.co.jp/english/products/cvt8.html


As for CVTs in general, the issue is really a personal one for the owner. Many are used to a shift pattern which a CVT doesn't have. Also, my guess is that a lot of buyers think these are just automatics and don't know the difference.

Once a driver adapts to the CVT all is good. Granted, the earlier models had their issues. The more recent versions are vastly improved.

Vehicles in which CVT's are usually found are mostly bought by customers like that.

 

[bbhero]

Disagree... A NA V6 like mine which has 258 lbs of torque and 270 hp.... Is lot easier on a transmission than a 4 cylinder turbo boosted GDI that makes 304 hp... Again... A 4 cylinder making more power than a V6.... Yeah... That is a huge change.... Not like typical 4 cylinder motors back in the day making 140 hp max....

Take that EXACT same set up and apply it in my motor... It would make like 475 hp...

 

[JTK]

Originally Posted by PimTac

Im guessing it's a Jatco CVT8 which is their latest model. There are a couple of variations.

https://www.jatco.co.jp/english/products/cvt8.html


As for CVTs in general, the issue is really a personal one for the owner. Many are used to a shift pattern which a CVT doesn't have...


I believe that particular CVT is in my 2016 Nissan Quest. It does have an actual shift pattern to it depending on your level of go pedal mashing.

I do agree with the above though. I've chatted cars with a bunch of people over the years who didn't know they owned a CVT.

 

[Ws6]

Originally Posted by bbhero
Disagree... A NA V6 like mine which has 258 lbs of torque and 270 hp.... Is lot easier on a transmission than a 4 cylinder turbo boosted GDI that makes 304 hp... Again... A 4 cylinder making more power than a V6.... Yeah... That is a huge change.... Not like typical 4 cylinder motors back in the day making 140 hp max....

Take that EXACT same set up and apply it in my motor... It would make like 475 hp...

Another thing is rpm. I remember back when the 4L60 and 4L65E were the thing in f bodies and corvettes. You could run slicks and spray and they lived a while even in stock trim with a big stall. Introduce a cam, and they died like dogs. The extra rpm when shifting really puts a hurt on an automatic. This is part of why I ak 100% content with my cx5 living its best life at 5500rpm shifts under WOT while others seem to wish for 6500+ shift points. As long as its making the power, lower rpm = more longevity.

 

[PimTac]

Originally Posted by Ws6
Originally Posted by bbhero
Disagree... A NA V6 like mine which has 258 lbs of torque and 270 hp.... Is lot easier on a transmission than a 4 cylinder turbo boosted GDI that makes 304 hp... Again... A 4 cylinder making more power than a V6.... Yeah... That is a huge change.... Not like typical 4 cylinder motors back in the day making 140 hp max....

Take that EXACT same set up and apply it in my motor... It would make like 475 hp...

Another thing is rpm. I remember back when the 4L60 and 4L65E were the thing in f bodies and corvettes. You could run slicks and spray and they lived a while even in stock trim with a big stall. Introduce a cam, and they died like dogs. The extra rpm when shifting really puts a hurt on an automatic. This is part of why I ak 100% content with my cx5 living its best life at 5500rpm shifts under WOT while others seem to wish for 6500+ shift points. As long as its making the power, lower rpm = more longevity.





Do you run yours in Sport Mode a lot? Our highways are more like parking lots.

 

[Ws6]

Originally Posted by PimTac
Originally Posted by Ws6
Originally Posted by bbhero
Disagree... A NA V6 like mine which has 258 lbs of torque and 270 hp.... Is lot easier on a transmission than a 4 cylinder turbo boosted GDI that makes 304 hp... Again... A 4 cylinder making more power than a V6.... Yeah... That is a huge change.... Not like typical 4 cylinder motors back in the day making 140 hp max....

Take that EXACT same set up and apply it in my motor... It would make like 475 hp...

Another thing is rpm. I remember back when the 4L60 and 4L65E were the thing in f bodies and corvettes. You could run slicks and spray and they lived a while even in stock trim with a big stall. Introduce a cam, and they died like dogs. The extra rpm when shifting really puts a hurt on an automatic. This is part of why I ak 100% content with my cx5 living its best life at 5500rpm shifts under WOT while others seem to wish for 6500+ shift points. As long as its making the power, lower rpm = more longevity.





Do you run yours in Sport Mode a lot? Our highways are more like parking lots.


No. I rarely use "sport mode".

 

[PimTac]

Neither do I. I do use it going up some hills in my area. It keeps the transmission in a lower gear and avoids any redundant shifting. I can use the manual mode as well. It depends on the situation.

 

[Ws6]

Originally Posted by PimTac
Neither do I. I do use it going up some hills in my area. It keeps the transmission in a lower gear and avoids any redundant shifting. I can use the manual mode as well. It depends on the situation.

My naturally aspirated cx5 got terrible mileage because if this. The turbo does much better, with its mad torque. Goes up all but the steepest hills in OD or 5th, never 4th.

 

[PimTac]

Originally Posted by Ws6
Originally Posted by PimTac
Neither do I. I do use it going up some hills in my area. It keeps the transmission in a lower gear and avoids any redundant shifting. I can use the manual mode as well. It depends on the situation.

My naturally aspirated cx5 got terrible mileage because if this. The turbo does much better, with its mad torque. Goes up all but the steepest hills in OD or 5th, never 4th.



I do notice the fuel economy drop with Sport Mode as expected.

A hill close to my house is just over a half a mile at a 11% grade. It has a number of twists and turns to boot. The other hills are not quite as bad but we do have some really steep ones, especially in the downtowns of both cities in the metro.

The turbo engine torque numbers tell the story. It took them a long time to decide to put that engine version in the CX5.

 

[bbhero]

Makes sense...
Lower rpm can equal longer longevity...

I will say this though... I routinely rev my car up to 4-5k rpm... Sometimes 5700 rpm.. I notice my car does do better running it harder from a standing start. Then... Slow down and cruise at regular rpm.. 2k to 2500.

 

[Ws6]

Originally Posted by PimTac
Originally Posted by Ws6
Originally Posted by PimTac
Neither do I. I do use it going up some hills in my area. It keeps the transmission in a lower gear and avoids any redundant shifting. I can use the manual mode as well. It depends on the situation.

My naturally aspirated cx5 got terrible mileage because if this. The turbo does much better, with its mad torque. Goes up all but the steepest hills in OD or 5th, never 4th.



I do notice the fuel economy drop with Sport Mode as expected.

A hill close to my house is just over a half a mile at a 11% grade. It has a number of twists and turns to boot. The other hills are not quite as bad but we do have some really steep ones, especially in the downtowns of both cities in the metro.

The turbo engine torque numbers tell the story. It took them a long time to decide to put that engine version in the CX5.

Yup. Love mine. I dunno the % grades of all my hills, but my drive is 300ft and 27%. Several hills getting in and out of my neighborhood are 1/4 mile and at least half that grade. Then we have more, etc. Hilly.

 

[PimTac]

Originally Posted by bbhero
Makes sense...
Lower rpm can equal longer longevity...

I will say this though... I routinely rev my car up to 4-5k rpm... Sometimes 5700 rpm.. I notice my car does do better running it harder from a standing start. Then... Slow down and cruise at regular rpm.. 2k to 2500.





My SkyActiv 2.5 barely exceeds 2000 at cruise. I will see it at higher rpm when on the freeway at 70mph when that is possible. Most engine do like to be revved up. That was the benefit of a manual transmission. You could wind them up. Fortunately I can go into manual mode and accomplish the same thing though I hardly ever do it.


Last week I spent about 6 hours on a local freeway trip doing 10mph or less. Sometimes the conditions just won't let you exercise the motor.