Skip to main content

Air Drag and Fuel Economy.. Really?

Driving back from work, this friday, My friend and I were having an interesting discussion. He suggests driving close to the car (tailgating ) in front and coasting there would improve the Fuel Efficiency because it reduces Air Drag. Spat came my answer: NO. My point was, even in a highway situation, this saving would be less when compared to the fuel expense to catch up with him if there was ever a break in speed (and that going back from work, speeds do break quite often). Not to mention the additional risk of an accident. Although I felt triumphant myself, He didnt bulge in. His example was, the cyclists in a marathon. They keep themselves together to reduce air drag and use lesser energy.

So in the weekend, I do this research. Apparently My friend was very correct on the Cyclists. It is scientifically proven that Cyclists get advantage by moving in groups and there by reducing the drag. Logically (theoritically too) it might sound appropriate to connect the dots to cars. But looks like it is not the case in all cases. If you are driving a car behind a truck, You will be reducing the drag. But practically, Most Trucks drive a standard 55 MPH or around it. Most cars now a days have a very well designed Frontal area to reduce the Coefficient of Drag (CD). At the speeds of the Trucks the cars of today are well designed for drag.

So what about tailgating other CARS. This case is even worse. Traffic situations like driving back from work, or weekend or holiday driving, would generally constitute a lot of heterogeneous traffic and breaking. So tailgating may *not* fetch you what you are looking for. Risk of an accident is much higher than when tailgating a Truck. On the other hand, On Highway, Edmuds gives tips, if you drive with less breaks and no switching lanes, you could achieve as much as 77MPH with better fuel economy otherwise.

In Conclusion, Over all, Coasting is much better than avoiding drag by Tailgating! Either way - Drive safe! And Drive green.

p.s: Did you Know? (My) Camry Hibrid has the best CD in its class!!!

image: treehugger.com
Labels:

Popular posts from this blog

Powered By

As it goes, We ought to give thanks to people who power us. This page will be updated, like the version page , to show all the tools, and people this site is Powered By! Ubuntu GIMP Firebug Blogger Google [AppEngine, Ajax and other Apis] AddtoAny Project Fondue jQuery
Read More >>

Decorator for Memcache Get/Set in python

I have suggested some time back that you could modularize and stitch together fragments of js and css to spit out in one HTTP connection. That makes the page load faster. I also indicated that there ways to tune them by adding cache-control headers. On the server-side however, you could have a memcache layer on the stitching operation. This saves a lot of Resources (CPU) on your server. I will demonstrate this using a python script I use currently on my site to generate the combined js and css fragments. So My stitching method is like this @memize(region="jscss") def joinAndPut(files, ext): res = files.split("/") o = StringIO.StringIO() for f in res: writeFileTo(o, ext + "/" + f + "." + ext) #writes file out ret = o.getvalue() o.close() return ret; The method joinAndPut is * decorated * by memize. What this means is, all calls to joinAndPut are now wrapped (at runtime) with the logic in memize. All you wa...
Read More >>

How to Make a Local (Offline) Repository in Ubuntu / Debian

If you are in a place where you dont have internet (or have a bad one) You want to download .deb packages and install them offline. Each deb file is packaged as a seperate unit but may contain dependencies (recursively). apt-get automagically solves all the dependencies and installs all that are necessary. Manually install deb files one by one resolving each dependency would be tedious. A better approach is to make your own local repository. Before you actually make a repo, You need *all* deb files. You dont practically have to mirror all of the packages from the internet, but enough to resolve all dependencies. Also, You have to make sure, you are getting debs of the correct architecture of your system (i386 etc) # 1. make a dir accessible (atleast by root) sudo mkdir /var/my-local-repo # 2. copy all the deb files to this directory. # 3. make the directory as a sudo dpkg-scanpackages /var/my-local-repo /dev/null > \ /var/my-local-repo/Packages # 4. add the local repo to sour...
Read More >>