+ Reply to Thread
Results 1 to 10 of 10
Thread: FEH/MMH AWD Questions
06-06-2008 06:43 PM #1
- Join Date
- Jun 2008
FEH/MMH AWD Questions
We're looking at replacing our 2002 Acura MDX with a more fuel efficient vehicle. We commute ~75 miles daily for work and the 20mpg we're getting with it just isn't enough. I split the time with my 07 Infiniti G35S which nets me 25mpg on premium.
My g/f really wants a Prius and we feel we could live with the reduced space going from an MDX to a Prius. It is a hatchback with decent cargo room. However, after reading about the 09 FEH/MMH updates, we're really considering it. Some of the advantages are: Fed tax credit (for the time being), more cargo room, SUV functionality, better brakes, better bad weather driving, mild offroading support for when we go camping, better looks.
The MDX is AWD which we like for when it rains and the few icey/snowy days we get, but in reality it's not a requirement. However, since the FEH/MMH has it as an option, it could be the feature that makes the FEH/MMH that much more appetizing.
Late last year we almost pulled the trigger on a Nissan Rogue AWD but decided against it because of the lack of automatic climate control (yeah pretty lame but we require it). With gas prices where they are, we want something even more economical than that so it's basically a hybrid or 35+ mpg car for us.
Anyways, my questions are:
1. Why is the EPA hit so significant with AWD on this vehicle. On every other CUV there's no more than a 1mpg hit city and hwy yet on the FEH/MMH it's 4/3. Please do not respond with the obvious like it's extra weight, extra mechanical load, etc. Every other car has that and my understanding is the FEH/MMH runs in FWD most of the time anyhow. Take a look at SUVs with way more significant AWD/4WD offerings and see that no more than 1-2mpg hits are being seen (example: Jeeps, 4Runners, etc...).
2. This is somewhat related to question #1, but my reading shows that the AWD system on the FEH/MMH works as follows: It runs in 100% FWD until it detects slip. Once slip is detected it routes power back as necessary. This system is essentially identical to the one found in the Honda CR-V and in my opinion not anywhere near as good as the systems found in the other CUVs where there's some predictive measures in place. Example: My MDX has VTM-4 which runs in FWD but with enough throttle or turn in it sends power back (before the slip). The Rogue is pre-programmed to start in AWD mode and use AWD when cornering and then dial back to FWD. Both of these examples will continue to send more power back when slip is detected. If the system is not predictive and is like the Honda CR-V's then it's not as good in my opinion. The CR-V is the worst off-road capable SUV/CUV around and could not get up a relatively trivial off-road hill in one of the big magazine tests. I know the FEH/MMH is designed for light off-roading which is more than sufficient for us, however, I personally can't stand systems that wait for slip. The Nissan Rogue's system is VERY nice.
Finally, our requirements for AWD are more for rain/snow/light mud then rock crawling or any of that stuff, but I can't stand waiting for traction control systems to come into play, etc.
All that said, I don't understand how such a basic AWD system can penalize the FEH/MMH so much. The RX400H is 27/24 FWD and 26/24 AWD and it has a more sophisticated AWD system than the FEH/MMH. So that covers an AWD hybrid offering and says it's not something related to AWD and hybrids. I'm really perplexed and have not been able to find a reasonable explanation.
Between the significant mpg hit and the relatively lightweight AWD system, I think I'd have to consider FWD.
Any insight from owners/non-owners is welcome.
Sponsored Links Remove Advertisements
06-07-2008 01:33 AM #2
Hey U235 I live in the
I live in the middle of nowhere Colorado on a farm, and I ordered a 09 FWD FEH - I personally do not know "ALL" of the mechanical reasons why the AWD FEH has the large parsitic AWD losses to the published MPG - but some are the obvious ones. Also some may take this vehicle offroad, - but dont, you will get stuck, look closely and you will see that it only reverses with the electric motor and as such will not back out of a rut or sand hole. Given that, you generally would not want to go where a 2wd vehicle would not go. Dirt roads or good trails are just fine. As to choosing AWD vs. FWD, I will say this: Even here with unplowed Colorado farm country roads - there was far less than 10% of days in the last year where the roads were not totally dry, there is just no need for AWD. simply based on that, I chose to go with the FWD instead of AWD - the fuel economy, potential extra repairs, higher price, better tax incentive - way offset the need for AWD. I Learned to "drive" (most people only think they can drive) with rear wheel drive cars, and tons of torque. And when there were no AWD or FWD vehicles AT ALL! - just a few 4x4 trucks. - I personally think AWD is a bandaid for knowing how to drive, and provides FALSE security to bad careless inexperienced agressive drivers , I see more AWD vehicles and SUV's in the ditch year round than any other type of car and I laugh !!. I drive a 2wd toyota truck around everywhere all the time Ice, snow, rain - even up to Vail to ski in the winter time and my Acura TL FWD only stops if the snow is 9 inches deep and no trail to follow. People are buying AWD for all the wrong reasons and vehicle manufacturers are loving it and continuing to feed the fire to increase vehicle costs and margins. AWD is not the panacea for knowing how to drive that people believe it to be. Dont fall into the trap - slow down when its wet & Icy Remember, this is a hybrid, driving very very slow is the object. if you are actually driving hard enough that you can feel the delay in a traction control system engaging your never gonna be able to obtain good MPG with the FEH. QUOTE: "I can't stand waiting for traction control systems to come into play" - if you want to drive fast and hard buy a BMW X5 XDrive V8 AWD at 19 MPG. -it does have climate control as well !. You might not like the FEH as a daily driver if your currently driving a MDX & a G35S. It took me 5 years of living away from suburbia before I realized I no longer needed my BMW740iL. and in hindsight, i never needed it. BUT it was rear wheel drive and it went ANYWHERE! in snow, ice, rain. I traded it for 4 horses and a horse trailer. I got the good side of the deal. There are those that flip off the guy hypermileing his pirus along at 40 MPH in the 50MPH zone, I smile, wave and give them the thumbs up, thats how you decide if a hybrid is for you.
06-07-2008 02:05 AM #3
The Ford AWD system is not
The Ford AWD system is not similar to the Honda system. There is a lot more electronic/computerized design in the Ford system compared to the Honda mechanical/hydraliuc pumping system.
Look at this link for the Ford information: http://www.ford-trucks.com/specs/200..._escape_2.html
This link for the Honda system: http://www.off-road.com/trucks4x4/Fe.../detail/465007
In your post, you admit the AWD is only for traction during rain and the occasional snow fall. If this is true, you would be better off with just FWD. I got an AWD system because I spend most winter weekends skiing-nordic skiing--and because the Escape Hybrid I located came with AWD and there was no other new 2005 model in this country when I purchased this vehicle in 2007.
As for a mileage hit with AWD, I notice a drop in steady and heavy downpours, more than in snow! This is due to the engaging of the rear wheels. I use Winter tires during the coldest months of the year. These tires have much bettter traction than the stock EcoPlus tires on the vehicle. This helps with minimizing wheel slippage. However, my winter tires have more rolling resistance than the stock EcoPlus tires. How much does the AWD system really "hit" the fuel economy is debateable. I have read 1-3 miles frequently, some claim 5mpg and who knows if the EPA ratings are a real world reflection? There are posters who have gotten over 40mpg with the AWD system. Then again, there are many environmental and individual driver factors that come into play when one refers to mileage ratings.
Remember, the hybrid vehicle should be cleaner burning than the gas only vehicle.
06-07-2008 02:14 AM #4
- Join Date
- Oct 2006
I believe the RX400H rear
I believe the RX400H rear wheels are only driven by a separate electric traction motor and is not recommended for off road use. The FEH/MMH AWD is driven by the electric motors and the engine except in reverse. There is no reverse gear, so the electric traction motor reverses direction to back-up. The FEH/MMH AWD is approved to be driven off road. For this reason, the drag on a I-4 Atkinson cycle engine causes more of a hit in MPG than the Toyota V6 SUV engine with its disconnected rear wheels.
With 75 miles of driving each day, I would forget the AWD FEH/MMH with todays gas prices. The FWD performs very good in snow and it handles mild off road use here in Florida very well. Never came close to getting stuck with my FWD '05 FEH. I would take the savings from the AWD (tax incentive, cost, mileage,etc) and order the new 2nd generation Navigational System with the '09 FWD FEH or MMH. The added power of the new 2.5L Atkinson cycle engine with no reduction in mileage should be very impressive. There are so many improvements in the '09, I ordered a Limited with Nav because my '05 is still worth much more than the gas Escape. When I say I'm getting the new '09, people are quick to ask me if I'll sell my '05. My wife will drive my '05 FEH till the 2010 Prius is available. Big improvements are coming for the 2010 Prius.
06-07-2008 02:29 AM #5
- Join Date
- Jun 2008
Thanks guys, your points are
Thanks guys, your points are dead-on. Our desire for an AWD car also somewhat stems from the fact that we may move to Sacramento or Denver to get closer to skiing in which we would require an AWD car. I know with good snow tires you can get up and down I-70, but I've done it several times and prefer AWD. In California, CalTrans shows no mercy for 2wd vehicles.
However, I'm probably better off getting FWD and if we move (20-30% chance) we'll get an AWD one and just deal with it then.
As far as the links posted above, it does appear the Ford's system is somewhat predictive, however, I recall reading somewhere that the FEH/MMH's AWD system is different than the regular Escape and ONLY powers the rear wheels with the electric motor (so I'm not sure that link clears the issue at hand). The fact that reverse is only via the electric motor is disconcerting as well, and could make it less capable than the CR-V in reality.
I think everyone is right, for our needs FWD is probably better, especially since the AWD system has so many caveats (mileage, tax credit, reverse issues, added cost, etc.). Also, in Texas it's much harder to find AWD on the lot so I'd likely have to order/wait for it. I know two months ago I could've easily got an 08 Hybrid on a lot, but no one had an AWD for us to test drive.
Thanks again and please continue to share your thoughts on the subject.
06-07-2008 05:00 AM #6
The reason the AWD Escape
The reason the AWD Escape Hybrid powers reverse only with the traction battery is due to the transmission. The Hybrid version has an electronic CVT that does not have a reverse gear. Otherwise the hybrid and non-hybrid AWD systems are the same. As for the Hybrid AWD system being less capable than the Honda CR-V is non-sense. The only issue with the AWD reverse is if you have a loaded heavy trailer and you are attempting to back up a hill. There is no problem going in reverse without a trailer in the AWD Hybrid in deep snow. I have this system on my 2005 Escape Hybrid and have backed up in 10 inches of wet snow.
06-07-2008 08:05 AM #7
I'd like to know if Ford's
I'd like to know if Ford's "Intelligent AWD/4WD" always means the same system, regardless of which vehicle you're talking about. In the Edge, which is marketed as a sporty, speedy crossover, Ford Says this about Intelligent AWD: "Using a preemptive slip strategy, the system continuously monitors vehicle speed, throttle input and steering angle to seamlessly deliver torque to the appropriate wheel even before wheel slippage occurs. The system also helps eliminate torque steer and helps balance the vehicle when cornering."
The Escape is marketed differently, and the press releases don't go into as much detail about Intelligent 4WD. BillyK's linked article does have this one little tidbit about the Escape: "...and can even predict slip and preclude it from happening at all."
Is the Escape's system as good as the MDX's? Maybe?
06-07-2008 08:49 AM #8
I've got a Prius and an
I've got a Prius and an Escape Hybrid 4WD. If fuel economy is your issue, the Prius is the way to go. We get almost exactly the combined EPA mileage (48 on the Prius, 28 on the Escape). Thus the Escape Hybrid uses 71% more gas than the Prius. Gas will probably cost $5 by next week =8-( so that's a big difference. The Prius holds a lot of stuff, but I've never driven it in snow. The Escape works well in Sierra snowstorms and is generally nicer to drive.
06-07-2008 10:14 PM #9
- Join Date
- Jun 2008
Thanks, AWD is becoming less
Thanks, AWD is becoming less of a concern. To Kermit, how would you rank the following between the Prius and Escape?
1. Driver and front seat passenger comfort/space
2. Road nice
3. Road/wind noise at 70-80mph
4. Rear passenger comfort/space
5. Features/Ammenities (assume both were fully loaded)
6. Build quality
8. Cargo volume with backseats up and down
06-07-2008 11:07 PM #10
- Join Date
- Dec 2007
I know I've posted these
I know I've posted these comments before, but to reiterate regarding my experience with an '08 FEH 4WD:
The 4WD system engages seamlessly and unobtrusively but works extremely well. We had the worst winter in many years here in So. Wisconsin and "Kermie" got us through some very deep snows, even backing out of the garage through 18" snow drifts.
You have to decide for yourself how badly you might need 4WD, of course, but the FEH 4WD system is excellent.