Hey Rick

I only use "N" for EV coasting but I have seen fuel shut-off in "N" after being in it in "D" first above 40mph. There are very few hills here in So. FL so I don't have a lot of experience in "N" and fuel-cut. In "D" during DFSO the eCVT controls engine idle because there is no fuel being injected. As your speed slows fuel starts being injected and takes over slowly from the wheels for NVH reasons.

As far as "N" coasting using up the battery SoC faster than "D" coasting it's because "D" coasting provides regen and actually charges the battery during decel. Our '09 FEH have much more electronics than my '05 and your old '07 FEH and that's why we are seeing a faster drop in SoC. In fact, the SoC drops in the '09 just as fast at a stop in EV. For this reason I put my FEH in Park and turn the key Off if I think it's going to be more than a few minutes at a stoplight, train, drawbridge or any long traffic stops. Remember I stated that I do a blip to start the engine from a stop? Turning Off the key will only delay EV for 30 seconds and I'm going to use my engine for charging and accelerating from that stop any way. If I'm sitting at a stop in EV for very long I'm going to use up to much SOC IMO. I've got in the habit of turning off the Key when I drive up to my bank teller because I could sit there for 5 min. or more.

If you can coast at 40mph and below in EV, shift to "N" and let the SoC drop because that is more efficient. I'm not sure about the '09 but I know in my '05 that regen in EV below 27mph does not show up on the Nav arrows. If you are over 40mph stay in "D" and get Fuel-cut and regen during decel coasting which is more efficient.

It's more efficient to coast longer in "N" in my '05 with even the engine running because the SoC does not drop as fast in my '05 and I don't get DFSO in "D" anyway. In fact, I am constantly shifting from "D" to "N" in traffic on the freeway in my '05 to improve my mileage. This does not work in my '09.

GaryG

 

i have a 05' 4wd feh. i'm averging winter 32 mpg, summer the highest so far is 38.5. i live on cape cod. i can experience harsh cold winters.

this winter the lowest mpg was 28. but only for a day, i brought it right back up to the low 30's.

 

Just and update on my 09 4wd...just took the same 5 hour drive twice but a week apart from each other and with a 20-30 degree difference in temps...got about 2mpg better with the warmer temp, no other real differences. not exactly a scientific study, just real world driving.

 

Wow - I'm still amazed at the mileage everyone claims for their 4WD FEHs and MMHs.

I drive carefully, use some of the tricks here, and my 08 MMH 4WD's tanks are always in the 26-28mpg range according to the nav system readout, which we all agree indicates higher than actual. I do see higher average readings during tanks (as high as 33 or 34 every once in a while), but never get even close to that per tank. Also, I seem to get better mileage on the highway than in the city, the opposite of what I'd expect on a hybrid.

Assuming for a moment that I am driving properly (that's a separate and valid discussion, but let's set it aside for the moment), are there things in the engine or charging system that I could take a look at for issues that might need fixing or tweaking to improve mileage? I note some klunks and hesitation in the transmission about half the time when shifting from L to D, and odd whines at bands of speed (35-40, 60-65, for example).

 

What air pressure are you running in your tires?

 

Ah - good question. 38-40 psi on the stock Contis.

 

Bmisf your getting about what I'm getting in my 09' 4wd, but I do see it noticeably better in the city, now sure why your better on the highway. I get 26-27ish on the highway and a couple higher in the city but like I said, the warmer weather is helping a bit also.

 

There can be a number of factors, from how hard you're accelerating and braking to how long your trips are, your terrain and how well you can avoid any drastic changes in speed, to your base driving style can all have a pretty dramatic effect on MPG.

Beyond that, there are other factors, like being smart about your battery management to ensure that you have enough charge when you need it and you're not drawing heavily from the ICE as you accelerate to recharge the battery at the same time, making sure not to overcharge in L, and other small factors that can play in your favor or against you.

Finally, the whine and other issues may in fact be legitimate problems. Try your Max AC, is it cold? (I mean cold!) If not, there may be a problem there, and if so, you're electric mode functions will be severely retarded. Your behavior doesn't sound quite right, but it's hard to say if it's a sensitivity issue or whether there's a real problem, I'm sorry to say.

Back to the question at hand, I recently somehow managed a 45 MPG tank recently, something I really wasn't expecting in the kind of cold we'd been having. Generally in the winters, with minus temps, feet of snow, I'm between 29-31. In Summers, with nice warm temps, I'm 38-45 MPG. Currently I'm at 37.1 with temps crazy all over the place. (Yesterday was 83, today 61) Though really, looking in the 4WD database should answer your question: https://www.greenhybrid.com/compare/...escape4wd.html (Even if the current status is nebulous)