Alex57r

I argee 100% but even with the low high end torque we have in our cars, 7th gear ratio is still too high.

Marc Collins

It's the low low-end torque. The 3.7 has decent torque at higher rpm's. The gearing is so short, though, that you still end-up with impressive acceleration from rest. You also have decent acceleration on the highway in 6th or 7th because it is revving in the mid-band. The trend (and the reason the 5 speed auto lasted as long as it did with its even higher rpms on the highway) in the US is that people don't want the car to have to downshift to move around another car at highway speed (not talking about a major pass on a two lane road here). Why this is the case in the land of the automatic transmission baffles me? People are willing to put up with noise and poorer fuel economy to get it in "sporty" cars.

Xerix

Could someone post a link to this +1mpg info? Ive been trying to find it on the net but can't. I just want to confirm. Or is this merely all just a rumor?

Thanks

Andrew

sonicloud

If you look at the spec for 2010 G, they are rated 19/27 not 18/26 like 09's.

Xerix

Actually, I found it. I thought someone would have put this in their summaries. Instead it was buried in the press release. You would think ppl would like an increase in mpg..... I know I certainly would. A little more icing on the cake for when i decide to get it :-)

2010 Infiniti G37 Sedan Facelift Revealed

Andrew

sonicloud

Here is the link:
Nissan/Infiniti News Room

da mayor

iTrader: (2)

i just finally took a nice drive yesterday w/ my '09 g37x coupe.... averaged 28mpg on the highway vs my 25mpg hwy for my '08 g37 coupe 5at....

maybe they went back to do testing and found the gas mileage for 2009 was a little underestimated?

G35leander

I disagree a bit with that first statement. I believe the G37 engineers had a tough time working out the best trade-offs between acceleration, fuel economy, real world "tractability", and marketing constraints (they wanted bragging rights against BMW, Acura, etc for having the highest peak hp). After having test driven an Acura TL SHAWD 6MT back to back with a G37 S coupe 6MT, I'm convinced Infiniti simply has a peakier, less efficient 3.7 liter engine than Acura. Both cars have the same EPA numbers, yet the Acura has a quicker final drive ratio, and the heavier, with 23 less peak hp, Acura feels quicker in all gears below 5000 rpm. If Infiniti can get VVEL on intake and exhaust, maybe they'll have to compromise less, and get a flatter torque curve across the rev range.

I still get a chuckle every time I read the brochure about "acceleration swell" - nice cover-up trying to mask the peaky nature of that engine as a "design feature". I just wish BMW could get their twin turbo up to snuff on reliability - I'm gonna miss that 335i torque curve... I kind of wish I could wait for the 2011 Buick Regal GS 6MT; but, then again, I don't think reliability on the GM DI turbo engines is any better than BMW's. ...probably a big reason why Nissan and Honda are going to be last to market with lower displacement direct injected turbos with nice flat torque curves and good fuel economy.

mw09g37

iTrader: (3)

i hate the acceleration swell...

there's gotta be an ecu program that gets rid of it..

G35leander

Software can only go so far when the variable timing and lift isn't on both intake and exhaust. The best way to get rid of acceleration swell is probably a different cam setup. Given that the marketers at Infiniti and likely the aftermarket industry don't know how to sell that lower peak hp with a flatter torque curve is a better trade-off for all-round driveability, we will likely not see such a product (marketing has only sold cars based on peak specifications for too long). Only die-hard gear head enthusiasts seem to understand flat torque curve with lower peak hp can be better (at least for non ***** to the wall street driving). Given 5% take rate on MT, we'd probably be talking a fraction of a fraction of a percent take rate on an aftermarket cam setup that broadens the torque curve at a cost of 30 or 40 peak hp.

Boomer-Bob

iTrader: (1)

Okay, I'm old and probably lost but...

And not meant to be argumentative, just looking for a better understanding of the flat torque curve vs. HP.

Just for the sake of discussion, I'm trying to think of two comprable cars, one that has significantly lower HP and higer torque than the other... with a better 0-60 or 1/4 mile than the high HP comparable?

I used to race against big block muscle cars. As I recall, the high torque 454's, 440's could "pull out tree stumps". But, the low torque high HP 426 Hemi usually had the advantage in the 1/4 mile with much better mph as well. Admittedly, the "drivablity" of the higher displacement / torque engines was better and they did "pull hard". But, that "swell" of a cammed Hemi was hard to beat even given it had a few less cubes.
Your thoughts?

woj027

I have a 2010 G37x. I'm still on the first tank of fuel, but the computer identified fuel MPG is currently 13.6 Mostly city driving. Trips of 10 miles or less.

G35leander

Horsepower is a measure of how fast torque is delivered. So, higher peak hp cars are indeed more powerful at their peak than lower peak hp cars. IMHO, the real measure for comparing overall power of a car is the area under the hp curve across the rev range. An engine with a peaky hp curve might actually have a smaller area under the curve than an engine with lower peak hp, but a flatter curve.

So, given the comments about big block muscle cars, it's quite possible the Hemis overall power curve still had a bigger power area than the GM big blocks. A hydraulic lifter big block Chevy had somewhere around a 6000 rpm redline (?), where a solid lifter better breathing Hemi gained maybe another 1000 rpm (or more)? No doubt with that much more range before a shift is required, plus higher peak hp, I can see why the lower displacement Hemi would win in quarter miles. However, on the street, tooling through 35 mph traffic, which muscle car would you rather have when you want to cut through slow traffic in high gear without downshifting?

As I said in earlier posts, a G37 with 7 speed automatic programmed well to recognize when the driver wants to be "spirited" will probably perform much better compared to an Acura with 5 speed auto. More ratios let you keep the engine on the boil to get that higher power out of it. The downside: the more you keep a peaky engine in peak power band, the worse the gas mileage. I get great mileage with my 335i because I can get decent hp and torque delivered without needing to run it above 5000 rpm.

I bet I could get 25-26 mpg on a G37 just like my 335i; but if I shifted around 2- 3000 rpm the majority of the time like I do my 335i, I'd probably never feel more than 175 hp, where I might be feeling something north of 200 in the BMW. If I buy a G37, I'm going to want to continue to feel at least as much power as I've been feeling in the BMW on a regular basis, which means I will be spending more time in the 5-7000 rpm range, which equates to probably 17-20 mpg, depending on how often I rev it up during my commute. I do know I've been perfectly fine running in 6th gear with my 335 above 40 mph. That car has 300 lb ft of torque or more available from 1500-5000+ rpm. Of course, I admit I do run the 335 to 6000 rpm on a regular basis, but I believe I'd feel compelled to do it more often in the G37 because that car will be so much less satisfying to drive in the lower rev ranges. To have the same power on tap in a G37 that I have in 6th gear at 40 mph in the BMW, I'd probably have to run it in 4th, or possibly 3rd gear.

Boomer-Bob

iTrader: (1)

G35Leander:

-Thanks for the post. I understand the comparison now. More low end torque, more spirited pull at low revs.; wider power band (area under the curve). All good!

Personally, I am pleased with the G power band and the performance especially for a N/A engine. (Not that I wouldn't think about ordering a TT model if offered.) Now just between the two of us, some of my best friends drive BMW's and I agree there are many advantages to FI and double VANOS. Cars running them are often compared to the naturally aspirated G's in car mags etc. and I take that as a complement.

Just yesterday, a neighbor was behind me leaving our street with his big block A/C Cobra followed by, I think a buddy of his, in a modded Viper. It came to me like a voice from the passenger seat, (where my wife was sitting) "you have to draw the line somewhere!"

dbg37

My G37 sedan can regularly get 19.5 - 20.5 mpg in city traffic, no highway.
This is not exactly stop and go, but only a 4.5 mile one way commute on inner city roads with several stop lights and such.

The mileage was approx 1 mpg lower when using the climate control during the summer.
I have less than 6K on the clock and used regular dino oil at the first change.
Following a more gentle break in period allowed the ECU to develop a gentler throttle tip in and that also helps with mileage.
The car is fairly well designed in that it keys to the driver, and the more modest you are with it, the more you will see higher mpg numbers.

You cannot have your cake and eat it too, driving continually with a heavy foot is never going to make for good mileage.

Also keep in mind that the G37 is not exactly a lightweight car, and the more you stop and go, the more you accelerate hard, the greater your cost in gas. Just because the car can out perform the greater portion of cars on the road doesn't mean it has to be driven that way.

If you drive modestly, and allow the auto tranny to upshift before 3k rpm 95% of the time, you will see better mileage. Use good grade of gas, and avoiding high concentrations of ethanol blends is also to your benefit.