Nissan mods the Versa: fuel economy up by 1 MPG

[trikkonceptz]

Ever since FE hit the mainstream, I had been suggesting to Scion / Toyota to start making bolt on mods to improve FE in the current line of cars. Rather than bust heads on a tranny flash to get 1mpg gain, why not develop a kammback spoiler, a set of wheel skirts, a better front bumper, small more aero mirrors, hell a back seat delete package, anything that has tangible gains without massive retooling.

[NeilBlanchard]

Hi,

Some new plastic bumper covers and grill pieces could be snapped onto cars. Fairing pieces could be added to side mirrors. Zigzag window trim covers, and hood gaskets, and streamlined wheel covers are easy, too. All these would add 5-7mpg.

Nissan is supposedly going to reduce their cars weight by an average of 15%. I think all cars could be reduced by 20-30% with smarter steel fabrications, smarter use of materials. Narrower and lighter, LRR tires should be used.

On defrost mode, the A/C should only come on automatically at maximum (if at all) and it should always be toggled on/off by the driver.

[MetroMPG]

Originally Posted by NeilBlanchard

All these would add 5-7mpg.

From what baseline? Talking about gains in terms of "MPG" can be misleading. 5 mpg more to a F-150 driver means a lot more than 5 more mpg to an Insight driver.

Better to speak in terms of % difference, where known.

/ot MPG rant

[NeilBlanchard]

Hi,

You're right of course! Thanks for the correction.

All these improvements can add at least 10% and as much as 25% to the fuel economy.

[MetroMPG]

Sorry - bee in my bonnet about MPG as a measure of efficiency.

[The Atomic Ass]

Originally Posted by Daox

That is what 5th gear is supposed to be, overdrive.

A taller final gear ratio will most certainly increase mileage. If you look at almost any BSFC map you will see this. Many newer vehicles gear their automatic transmissions drastically lower than their manuals. This helps keep their mileage up when traveling on the highway. My guess is they don't do it on manuals because it may cause the operator to have to manually shift on hills like you mention.

IMO loose a few mph on the hill and get better mileage. I wish we had that choice.

Torque isn't as much an issue in larger engines, (I'm sure my father's Bravada could be geared significantly taller, 2K @ 60 is probably not necessary, and same with my mother's Eldorado), but his 2.2 S-10 can't go much lower. The engine starts to lug in the upper gears as high as 1,800 and turns in reduced FE when short shifted.

Similar issue with the Ninja 250 I had, I re-geared from 14/45 to 15/41, and while the take-off was actually better, and the first 5 gears more usable, I had to forgo using 6th altogether as the engine would not hold speed if it was under 7K.

[gascort]

My mustang has a very high 5th gear overdrive. (same with the corvette and Camaro). I drive it at 1500rpm to cruise at 60 mph. The vette, with better aero, sits just above idle on the highway. It would be nice to see gearing like this in smaller cars!

Originally Posted by MetroMPG

... I'd bet that most North Americans who drive stick don't know enough to downshift to pass or get up a steep enough highway (top gear) grade without lugging.

I agree, sadly. One of my friends was driving my mustang on a road trip (she had a 5-spd accord) and she didn't know what to do when the car started lugging while hill climbing at 50 mph in 5th.
However, this problem would be solved within the first few times a person drove the car, as they learn about torque/hp at different rpms through experience.

[MetroMPG]

More Versa tweaking:

ABG reports Nissan will be offering a 1.6L engine (107 hp) in place of the 1.8L (122 hp) in a new "stripped down" version of the car in the US, at least.

Unfortunately, the only manual transmission available on the 1.6 is a 5-speed, where the 1.8 gets 6 cogs.

The EPA ratings for the different engines now look like this:

1.6L M-5: 26 mpg (US) city (+0.0%) / 34 mpg (US) hwy (+9.7%)
1.8L M-6: 26 mpg (US) city / 31 mpg (US) hwy

1.6L A-4: 26 mpg (US) city (+8.3%) / 33 mpg (US) hwy (+3.1%)
1.8L A-4: 24 mpg (US) city/32 mpg (US) hwy

1.8L CVT: 27 mpg (US) city/33 mpg (US) hwy

Interesting news if only because it makes me unreasonably hopeful that Honda and Toyota might follow suit with smaller engine options in the Fit & Yaris...

The horsepower wars are over! Everybody lost!

[lovemysan]

I drive a car with a tall overdrive and to the average person its a pig. Peak torque arrives at 70mph @2450 rpms in 5th. It labors on the interstate. With 2-3 people and some luggage it gets worse. Requiring a downshift to 4th on average hills to maintain the speed limit. The average driver simply would rather have a little more power in place of 5-10% bump in FE. If I could install a longer overdrive for FREE i wouldn't do it in this car. Its right where it needs to be. If it was in taller it would hurt FE.

[cfg83]

MetroMPG -

Originally Posted by MetroMPG

More Versa tweaking:

ABG reports Nissan will be offering a 1.6L engine (107 hp) in place of the 1.8L (122 hp) in a new "stripped down" version of the car in the US, at least.

Unfortunately, the only manual transmission available on the 1.6 is a 5-speed, where the 1.8 gets 6 cogs.

...

The horsepower wars are over! Everybody lost!

I don't mind the loss of a gear as long as the last gear is the same in both trannys.

I have the same 5th gear as lovemysan, and it's definitely at it's limit. But, since I use it as a commuter on the flat most of the time, I don't have to resort to 4th as much.

CarloSW2