wowzer

Is it the functioning of the AWD or is it the weight of the SH-AWD that causes such a dramatic loss of highway MPG? Does 150lb create that much loss of MPG on the highway? Or is it the functioning of the SH-AWD causing tire drag that loses the MPG?

Just curious.

Quandry

According to the specs highway MPG is the same for the SHAWD and the FWD V6 is the same 25 MPG. For city driving the added weight is the primary contributor to the difference.

iforyou

iTrader: (1)

I think SH-AWD is more like 250lb?

Also, the engine has to use energy to spin the extra driveshaft, gears, etc.

weather

I also agree that I think it is more than weight related and some mechanical linkage is partly the culprit for the deterioration of MPG. I mean 200lbs seems to be the normal weight for most now....does this mean having one person in the car affect the MPG that much?! At 115 lbs, I am not overly worried *lol*

accord1999

Acura did a good job in reducing the weight penalty, in Canada the Elite SH-AWD is 3785 lbs vs 3631 lbs for the Elite V6.

That's probably the main reason. Still when cruising on a flat highway in warmer conditions (>10C), I've found the SH-AWD to easily beat 31 mpg.

jshaw

^^ That figure also includes (at least in the US) a slightly heavier (and larger) AGM battery as part of the start-stop system.

Rocketsfan

Keep in mind the SH-AWD's mileage would be even worse without the start/stop functionality of the engine that the non-SH-AWD's don't have.

ITdude

I think it is more than just the weight difference. You lose some efficiency transferring power to the rear wheels. A FWD car is generally more efficient than a RWD. Acura uses some tricks to improve fuel economy on the highway.


This engineer does an excellent job of explaining how the SH-AWD works and should explain the difference you see from it as compared to the FWD version

www.youtube.com/watch?v=Yz9ol5zy5nk" target="_blank">www.youtube.com/watch?v=Yz9ol5zy5nk

wowzer

Is. There a way to turnoff SH-AWD? This way, you can turn it on when it starts torain or snow, and not waste extra power. I guess this is wishful thinking...

ITdude

^^^Sorry, I meant to just paste in the URL. I didn't realize it posted the actual video in the post.

Stew4HD

No, you can't turn off SH-AWD nor do I see why you would ever want to. The loss in MPG is not significant but the advantages are, even on dry roads.

justnspace

iTrader: (1)

lol at turning AWD off.

simply buy a FWD to turn it off.

AZuser

But... but... turning off SH-AWD will save 3 MPG's!!!! (based on EPA combined MPG rating). If you drive 15,000 miles per year, turning off SH-AWD will save you 64.2857 gallons per year. If gas is $3/gal, that's a savings of $192 per year!!! Don't you know that that can make or break some people?

Nexx

If you're this concerned about the fuel economy you shouldn't be looking at this kind of vehicle. Prius my friend, Prius

Stew4HD

Or.. buy an SH-AWD and use regular!

accord1999

Trucks can do this as well as some cars/SUVs; but in general the better AWD systems are always full-time. Part-time AWD systems in cars/SUVs are almost always held in lower regard.

wowzer

My reason for asking is that I have a new job that is 22 miles from home. If I drive 2 times for 5 days a week, that comes out to 220 miles in a week. If a tankful of gas (I don't care regular vs premium), then I need at least 440 miles of commute (mostly highway, but in Long Island, NY so that is equivalent of city driving for most of US) if I am to avoid filling up more than once every 2 weeks (it's nasty to fill up during polar vortex in winter and heat waves in summer). This is my sole reason for inquiring about the AWD.

Since I live in the suburbs of NYC, snow and freezing rain is likely, thus, I'd prefer the AWD. However, I just fall short of mileage at 419 miles if I multiply the AVG MPG and the Fuel Tank size (24 x 17.2 = 419). The FWD just makes it under at 436 miles per tank...but since most of my driving is highway, I think this will be enough.


For the record, I am the original owner of a 2002 TL-S, but I dont get anywhere enough miles per tank for that car.


PS I also own a Prius, but I dont WANT to drive that car anymore (I used to commute into NYC...). :-)

wowzer

I liked the V6 a little more than the 4 cylinder...but the 8SPD is on my shopping list.



IT Dude, thanks for the video. That was informative...

YeuEmMaiMai

AWD has

1. More mass to move compared to a FWD or even a RWD car on the same chassis/model
2. More driveline loss from extra rotational losses.
3. there may or may not be different gearing involved. For example my legacy accelerates like any other 4cyl fwd car but it is geared lower to do so. 70mph - 2800rpm on the tach

BEAR-AvHistory

WOWZER your thought is not all that of the wall just in the wrong pew.

You can shut, should, down a true 4X4 system but not many AWD's. They are built for different purposes. AWD is generally a driving aid so you want it there all the time.

True 4X4 is off road, snow, mud traction oriented typically having high & low ranges & are not needed all the time.

I have two 4X4 one with an auto function one without & one AWD. Both the 4X4's have warning labels not to use them in 4WD on dry pavement. This is because the wheels can lockup if they can't slip a little.

The Ranger has 2WD - 4WD high range & 4WD low range. The transfer case is operated from a rotary switch on the dash.

The Expedition has the same functions with the addition of an Automatic position on the switch that enables the 2WD to switch into 4WD high if it detects slippage. Once the slippage is managed it reverts back to 2WD.

BTW Motor Trend has a very nice write-up on the 2016 NSX really like the 4 exhaust finishers #19 on the # 18diffuser, much like the new StingRay



Might it mean that finishers are coming back at mid cycle to the TLX?

accord1999

How long does your commute usually take? My commute of 14 miles averages about 45 MPH and I get close to 31 MPG in warmer conditions (>10 Celsius) with a TLX SH-AWD.

To be certain, I would try to get an extended test drive from a dealer and drive your commute to see what kind of mileage you could expect. You'll also need to consider the effect of cold weather, which will noticeably impact fuel consumption.

wowzer

The commute is really highway---around 60mph for 90% of the trip. I haven't even started at this new job, so I dont know how my TL-S will do in terms of mileage. Usually, I'm lucky if I hit 20MPG in the TL-S (I just love the way the car accelerates...).

accord1999

With that much highway miles,, if it's at all free-flowing then you'll be looking at closer 30+ MPG even with the SH-AWD.