Why am I getting worse MPG with a CVT then a manual?

[miri]

I used to have a 2005 Scion TC which is rated 20 MPG in the city. I averaged 25 MPG in the city shifting between 2500-3000 RPM.

I now drive a Nissan Rogue, rated 22 MPG in the city and I accelerate slowly and the CVT usually shifts around 2000 RPM. So far I have gotten 22/23 MPG in the city on the same route.

Why did I get such better MPG on the same route with a manual? Not only did the manual have much better MPG but it had much better acceleration as well shifting close to 3000 RPM. Why is the Rogue rated higher city MPG then the Scion?

 

[woodie1]

1st idea - Is the Rogue new? If so, the engine may not be broken in yet.

 

[ElFenix]

rogue: cute ute, ~3300 lbs
tc: hatch/coupe ~2900 lbs

no, i'm sure an extra 400 lbs wouldn't have anything to do with it



also, how new is the rogue?

 

[LTC8K6]

Mileage calculations are difficult at best.

The idea that your TC beat the old EPA numbers by 5 or 6 seems unlikely.

Old 2005 Tc ratings 22/25/29
New 2005 Tc ratings 19/22/27

 

[Bignate603]

One was a coupe, one was an SUV. Worse aerodynamics, bigger tires, more weight, probably a bigger more powerful engine, all end up eating more gas. SUVs get worse gas mileage, it's a fact of life. Go talk to JulesMaximus about that

 

[miri]

Originally posted by: ElFenix
rogue: cute ute, ~3300 lbs
tc: hatch/coupe ~2900 lbs

no, i'm sure an extra 400 lbs wouldn't have anything to do with it



also, how new is the rogue?

Originally posted by: Bignate603
One was a coupe, one was an SUV. Worse aerodynamics, bigger tires, more weight, probably a bigger more powerful engine, all end up eating more gas. SUVs get worse gas mileage, it's a fact of life. Go talk to JulesMaximus about that

I know the rogue is a larger car. But I am going by current EPA MPG. And by current EPA ratings, the Rogue is more fuel efficient.

The Rogue was purchased new in May 2008.

 

[miri]

Originally posted by: LTC8K6
Mileage calculations are difficult at best.

The idea that your TC beat the old EPA numbers by 5 or 6 seems unlikely.

Old 2005 Tc ratings 22/25/29
New 2005 Tc ratings 19/22/27

Weird isn't it?

When I drove from Virginia to California, I averaged 34 MPG going averaging 70MPH with all my personal belongings in my car weighing it down. How it got over 7 MPG higher than the rated highway MPG I do not know. I sorta regret trading the car in now.

 

[HannibalX]

Originally posted by: miri

Originally posted by: ElFenix
rogue: cute ute, ~3300 lbs
tc: hatch/coupe ~2900 lbs

no, i'm sure an extra 400 lbs wouldn't have anything to do with it



also, how new is the rogue?

Originally posted by: Bignate603
One was a coupe, one was an SUV. Worse aerodynamics, bigger tires, more weight, probably a bigger more powerful engine, all end up eating more gas. SUVs get worse gas mileage, it's a fact of life. Go talk to JulesMaximus about that

I know the rogue is a larger car. But I am going by current EPA MPG. And by current EPA ratings, the Rogue is more fuel efficient.

The Rogue was purchased new in May 2008.

The EPA is full of shit. Their numbers are estimates only and 9 out of 10 times do not reflect real world driving. They should be used as a guide only.

 

[Uhtrinity]

I averaged 25 MPG in the city shifting between 2500-3000 RPM.

That right there would be my bet. The lower you can keep your rpms (without lugging), the better your mileage is likely to be. I try to keep my rpms between 1000 and 2000 when in town. With a CVT you are very limited on where you can keep rpms as the car will automatically adjust the ratio. This is far from the most efficient for all conditions.

 

[desy]

On the Nissan Versa forum lots of complaints from those with CVT same issues.
Seems CVT doesn't like city drving much.
Mine has the 4 speed auto and mileage is as advertised

 

[spidey07]

Manuals are more efficient, less power loss.

 

[Throckmorton]

A CVT doesnt have a torque convertor AFAIK

 

[Uhtrinity]

Originally posted by: Throckmorton
A CVT doesnt have a torque convertor AFAIK

But it still won't be the most efficient for all conditions.

 

[dud]

CVT = automatic transmission
Manual = manual transmission

Manual transmissions usually get better MPG then automatics do.

 

[LTC8K6]

"Manual transmissions usually get better MPG then automatics do."

That's nowhere near the solid statement it used to be a few years ago.

In the case of the Tc, the automatic was rated better than the manual in the city and the same on the highway.

These days, the auto is often rated better.

 

[dirtboy]

Different cars equal different mileage; it has nothing to do with the transmission. Compare a CVT TC to a manual TC, not that you can, or a manual Rogue to your CVT Rogue. Then you'll know for sure.

 

[Jeff7181]

Originally posted by: miri
I used to have a 2005 Scion TC which is rated 20 MPG in the city. I averaged 25 MPG in the city shifting between 2500-3000 RPM.

I now drive a Nissan Rogue, rated 22 MPG in the city and I accelerate slowly and the CVT usually shifts around 2000 RPM. So far I have gotten 22/23 MPG in the city on the same route.

Why did I get such better MPG on the same route with a manual? Not only did the manual have much better MPG but it had much better acceleration as well shifting close to 3000 RPM. Why is the Rogue rated higher city MPG then the Scion?

Wait... the CVT shifts? That's new...

 

[Jeff7181]

Originally posted by: Throckmorton
A CVT doesnt have a torque convertor AFAIK

They do, they just lock up sooner than a traditional automatic. At least, Nissan's does. Not sure about other manufacturers. They also still have pumps. Nissan's CVT is electronically controlled, but it still uses fluid pressure to adjust ratios between pulleys... just doesn't need to build 80-100 psi to apply clutches.

 

[Gamingphreek]

Originally posted by: Jeff7181

Originally posted by: miri
I used to have a 2005 Scion TC which is rated 20 MPG in the city. I averaged 25 MPG in the city shifting between 2500-3000 RPM.

I now drive a Nissan Rogue, rated 22 MPG in the city and I accelerate slowly and the CVT usually shifts around 2000 RPM. So far I have gotten 22/23 MPG in the city on the same route.

Why did I get such better MPG on the same route with a manual? Not only did the manual have much better MPG but it had much better acceleration as well shifting close to 3000 RPM. Why is the Rogue rated higher city MPG then the Scion?

Wait... the CVT shifts? That's new...

Well technically it has infinite shift points within a set of boundaries

Seriously though- just because you have a CVT doesn't magically make the engine more efficient.

2.4L 160HP DOHC (Probably includes VVT-i) for the TC
2.5L 170HP DOHC (Not sure what Nissan calls its Variable Valve Technology)

So it is a slightly larger engine, not to mention you are using an SUV over a Sports Coupe/Sedan.

As far as better acceleration-- again you are comparing a Sports Sedan to an SUV. A CVT transmission will help in a lot of areas, but it doesn't magically make a car faster.

Also, you say it accelerates better while shifting at 3000RPM. How are you judging this acceleration. If you are going WOT for both cars, they should be "shifting" at much much greater than 3000. Also keep in mind, that they are GOING to "shift" at different RPM's. This is a different car with a different transmission and gear ratios.

-Kevin

 

[ashishmishra]

Originally posted by: LTC8K6
"Manual transmissions usually get better MPG then automatics do."

That's nowhere near the solid statement it used to be a few years ago.

In the case of the Tc, the automatic was rated better than the manual in the city and the same on the highway.

These days, the auto is often rated better.

Unfortunately, a lot of this has to do with the different final drive ratio between Manuals and Automatics. If you check the Manuals are most of the time running on a shorter final gear ratio than Automatics. Which gives them much better acceleration than automatics but hurts them in terms of fuel economy.

Case in point:

Ford Fusion 2.3L I4

Manual
1st: 3.31:1
2nd: 1.84:1
3rd: 1.23:1
4th: 0.97:1
5th: 0.76:1
Final Drive: 4.39:1

Automatic
1st: 3.50:1
2nd: 1.86:1
3rd: 1.24:1
4th: 0.90:1
5th: 0.69:1
Final Drive: 3.86:1

If you look at the 5th gear of both and then look at the final drives, the manual looses on both front in terms of gearing, yet looking at the EPA rating for the two:

Manual: 20/29
Automatic: 20/28

The manual still beats the automatic on highway by 1 mpg, now imagine if they had identical gear ratios. If the gear ratios are identical then the manual will absolutely murder the automatic in terms of fuel economy.

**Speculation 1** I think the automakers reasoning behind this rather strange choice is that they want to keep both markets happy. Only sporty drivers want manuals, so they get a zippier car than the automatic version. Normal drivers don't feel that they are loosing fuel economy by opting for the automatic.

**Speculation 2** By keeping the fuel economy numbers identical they will continue to sell a $1000 automatic option in cars, and normal people won't be motivated to learn stick.

 

[LTC8K6]

The EPA ratings are actually the same for the auto and manual 2007 2.3L Fusion. 23/31 under the old ratings and 20/29 under the new.

The gear ratios don't have anything to do with selling auto trannys, imo.

 

[LTC8K6]

What's interesting is that the 2008 Fusion 2.3L with the 5 speed auto does worse than the 2007 with the 5 speed auto on the highway.

 

[dud]

Originally posted by: LTC8K6
"Manual transmissions usually get better MPG then automatics do."

That's nowhere near the solid statement it used to be a few years ago.

In the case of the Tc, the automatic was rated better than the manual in the city and the same on the highway.

These days, the auto is often rated better.

The key to your argument is "These days, the auto is often rated better."

There is a distinct difference between "rated" and "actual" MPG ... based upon personal driving habits, etc. When I buy a new car for my wife or myself I always prefer the manual as I almost always get better MPG and a manual is so much more enjoyable to drive.

 

[LTC8K6]

Well, these days the auto often actually gets better mileage, too. It's also often just as quick to accelerate.

Be that as it may...

Your mileage varies greatly with all sorts of factors involved, and calculating it yourself is tricky at best.

I think we've all heard the story about how much better it is to drive manuals...

How unmanly it is to drive an auto...

Drive what you like. People have to know their limitations, to paraphrase Dirty Harry.

I can easily see a person not wanting to bother with a manual on today's crowded roads. I wouldn't blame them a bit.

I can't stand manuals, myself. Love the pleasure of driving with a good auto that does what it's supposed to do and crisply. Love those quick, perfect downshifts for passing.

 

[BlahBlahYouToo]

he's not asking why the tC is getting better fuel economy than the rogue. that's an obvious answer - size of the vehicle, engine, manual/auto.
he's asking why the FE in the tC is better relative to the EPA, than the rogue is to its EPA rating.

my guess is the rogue is still not broken in yet, the EPA ratings are inaccurate, and a manual is easier to eke out more gas mileage than an auto (easier to exceed EPA ratings).