ScanGauge WindGauge - Fuel Economy, Hypermiling, EcoModding News and Forum

Who · 01-21-2008, 01:46 AM

As a long distance cyclist, I never tended to give the wind much thought once strapped back into the rolling cocoon. On a motorcycle I rarely thought about it except on 2 lanes roads with crosswinds coming from the left so that truck wakes would never surprise or a time in South Dakota were able to converse quite well at over 70 mph (and that huge tailwind was attached to a major storm).

Today I was coming back to Toronto from the east and I couldn't crack an average of 10 LHK (23Â½ measly MPG) where I'd usually be 8.5 to 9 and most of you would be under 5. I was averaging 90 KPH / 56 MPH, keeping LOD moderated over all the rises, but my mileage was 10.1 LHK and it was also pretty cold - the IAT was -4C/24.8Â°F, coldest I've been out with a ScanGauge. Anyway, I was starting to wonder just how much the denser air affects my un-aero blob but looking at the weather logs in that area, there was a WNW wind of 22-32 KPH / 15-20 MPH so there was the missing 3 or 4 extra easy highway miles per gallon I was expecting.

A load type gauge should really be standard in every vehicle. On my bicycle it's pretty obvious, in a car it isn't, but with it, you really become aware of which roads aren't as flat as they appear, the impact of accessories, and even the wind, although it'd be nice to have a pitot tube like on a plane - so that it doesn't make you start to wonder at what temperature the air gets so thick that mileage plummets!

I want a NAV to help assess grade info but none of the main ones like the TomTom seem to have any altitude or grade info.

Excuse the ramble...

MetroMPG · 04-02-2008, 11:08 PM

Actually, Dan (krousdb) had pitot tube installed in at least one of his cars (probably 2). And I know he wasn't the only one.

Who · 04-02-2008, 11:13 PM

A pitot tube would cause far too much drag for such a small svelte smooth vehicle as mine.

MetroMPG · 04-02-2008, 11:16 PM

Princess and the pea?

diesel_john · 04-03-2008, 01:30 AM

looking at vacuum, you get a feel for changes need a big dial though. the diesel is tough to drive, my fuel pedal is constantly changing all day long, no vac., no cruise, no nothing. now even no smoke, with the bio-diesel.

RH77 · 04-03-2008, 02:38 AM

Quote:

Originally Posted by Who

A pitot tube would cause far too much drag for such a small svelte smooth vehicle as mine.

Puh-lease. Knowledge is power, so apply it to the vehicle and P&G

Truly, vehicle speed versus headwinds can mean the difference between a Dodge Avenger getting 29.4 MPG and the identical twin (Sebring), getting nearly 38. It's all wind dude.

RH77 "Headwind77"

s2man · 04-03-2008, 06:38 AM

My browser's home page is three weather sites, but I never paid much attention to the wind vs my mileage. When I put on my permanent grill block I had super FE on my morning commute. Woohoo, it worked. Then I realized I had a tail wind on the way to work. LOL. I"ve paid closer attention to wind since then. I now vary my route, or aggressively seek out a truck to draft, if winds are contrary.

tasdrouille · 04-03-2008, 09:21 AM

Just watch the LOD on the SG. Your "usual" 8.5-9 LHK corresponds to a specific LOD in 5th speed. If you want to compensate for the denser air or wind to keep roughly the same mileage as usual you just have to slow down till your LOD matches what you usually get and voila.

Who · 04-03-2008, 10:23 AM

RH77, I drive an aerodynamic disaster...

RH77 · 04-03-2008, 02:45 PM

Quote:

Originally Posted by Who

RH77, I drive an aerodynamic disaster...

I know, I'm just being a pain

Mainly, my point is the ability to know your headwinds, to slow to a target "Indicated Airspeed", which could outweigh the small tube's drag (or even make subtle, inconspicuous aero mods to outweigh it).

For example, your target aero combined speed is 120 kph. If the headwinds are 20 kph, you know to slow to 100 to hit your target -- or at least slow a bit.

It's just another feedback device.

RH77