Hypermiling the small SUV: post your experiences here!

[dobsont]

These vehicles present unique challenges for the hypermiler -- additional driveline drag, parasitic aerodynamics, etc.

Nevertheless, there are a bunch of us on this site that drive 'em.

So let's discuss what works, what doesn't.

Post your numbers. Post your gripes. Post your tips and your triumphs. Let's talk SUV.

[dobsont]

Alright, here's one. I've seen numbers in excess of 40mpg on the highway. Strong tailwind, 100kph, constant state cruise. Wish I'd thought to try some high speed P&G.

I like to think of the CR-V as a sail. It feels good to imagine that I'm getting more push from a tailwind than a sedan might. Naturally, 'imagine' may be the operative word here...

[JusBringIt]

I have reason to believe this only works if you're traveling slower than the speed of the wind. if you're going faster than the wind, you just have less wind drag, and since the sedan has a more sloping rear, it does have even less wind drag.

[dobsont]

Hey Jus. You may very well be right. I'm no scientist, so I can't pull out a burner and burn up some stuff and figure it out... .

***

By my reckoning, tires are particularly important (not that they aren't on other vehicles, of course).

Light truck tires show up in the fitment charts that tire shops use. It's probably a no brainer to most people here that they'd be a bad choice for FE.

I spent some time thinking about tires for our CR-V, and decided to go with Michelin Hydroedge -- partly because I found a coupon that made them pretty cheap to buy, partly because of their wear rating, and partly because i'd heard people say they noticed an increase in mpg. According to Wayne's rolling resistance shootout they fare pretty well. I'm noticing a pronounced difference (over snow tires...duh, ya think?) in my coast distances, so I suspect I'll see the difference at the pump. However, too many variables are changing at this time of year to really be scientific about the whole thing.

[JusBringIt]

speaking of tires i do have some oversized yokohama snow tires on right now, I'll be putting on summer tires as soon as i have the funds available. they def. hurt FE, so im looking for at least a 10% gain once i get to summer and with sgII it should give me an additional 10-15% based on wayne's analysis of the average increase. it may be less but a gain nonetheless. i think suv's would gain a lot from covering up those wheel wells along with the basjoos treatment. .

[hobbit]

Got a question for y'all: last year I happened to notice that
the big FSP that the CBS guys drove to Hybridfest in had tires
on it sidewall-rated for 85 PSI or something in that area. What
do your tires generally call for, and how does that compare to
what the door placard says? Seems likely that there's some
serious advantage just waiting to easily be taken there.
.
_H*

[xcel]

Hi Al:

___It depends what kind of load the truck was designed for. The ¾ Ton on up stuff usually has the 80 # sidewall tires. The consumer oriented SUV’s and P/U trucks are stuck with 35 and 44# max sidewall. That I have experience with anyway.

___I run the MDX’s X-Terrains (35# max sidewall and 30#'s on the doors IIRC) at 45 – 50 #’s if that helps.

___As for pulling big numbers from an FSP, get them out on the highway in a slow speed DWL/DWB cruise and don’t ever let them stop!

___Good Luck

___Wayne

[2TonJellyBean]

D rated tires typically have a 65 psi sidewall max

E rated tires typically have a 80 psi sidewall max

I'm toying with the idea of changing tires.

Current tires are 235/70R16 - 29.1" tall and 32 pounds each.

I'm thinking about going with 215/85R16 (D or E rated). I'm not sure what they'd do to the ride, although the ride is already stiff from running 55 psi on 44 psi rated tires.

Most 215/85s are around 30.4" tall but I've seen models from 29.9 to 30.7" tall.

The weights range from 28 to 48 pounds with most being around 41-42 pounds.

Vehicle is a bit undergeared so taller tires would help there, but I'm not sure if the aero woluld suffer even more with the vehicle up another 7/10" or so...

The downside of the extra gearing would be having to hit 65 KPH instead of 62 KPH to get into 5th, then 5th would only hold down to 53 instead of 50... much of the daily driving is short urban trips with a 50 KPH (31 MPH) speed limits.

[Scirocco]

Last night I took home a 5 spd manual 2003 CR-V AWD, to replace my 2000 Explorer that got totalled a couple of weeks ago (~ 17 mpg). The Escape hybrid was out of my budget. I am gathering baseline data now (still driving on my first full tank), trying to drive as I always have for at least a couple tanks. I have been one of "those" drivers that no one here (or probably anywhere) really appreciates sharing the road with, as I tend to drive fairly agressively. I hope to use the techniques and tools that I see here to see just how far I can push the feul economy of my new ride, and give me incentive to alter my driving habits in a positive way. My commute is probably 75% hwy miles so I'm hoping that will give me an added boost, as well as the flexibility of the manual transmission. Hopefully by the time I burn thru the first couple tanks (probably two weeks), the next group buy on the scan guage will happen and I will be able to put that to use early on. I feel somewhat out of place with all the hybrid drivers here, but I'm going to make the most of what I have got... I will console myself in the fact that we replaced my wifes 94 Accord a couple years ago with an 06 Prius (avg 48mpg lifetime so far).

Sorry to ramble, but I'm glad to see that I am not a lonely statistical outlier... I'll post again as I get more data.

[2TonJellyBean]

Scirocco, if you haven't checked out ScanGauges yet, give one some serious thought.