Old-School: $11 of Mods + New Tires = 25% Better Fuel Economy
by Michael Graham Richard, Ottawa, Canada 
on 03.17.08
The 1973-1974 oil crisis made a lot of people start to pay attention to fuel economy for the first time. In its March 1974 edition, the magazine Car and Driver had a look at some simple DIY modifications that could be made to one of the economy cars of the time, the Ford Pinto (ack).
They came up with six fairly simple and inexpensive suggestions (see below). Not all of them are as applicable today, but some are (lots of cars with bad aerodynamics on the road), and the general spirit of the exercise is worth recapturing. Efficiency isn't enough - we need a much bigger leap forward - but it's better than nothing in the meantime, and even much cleaner cars (Plug-ins, EVs) would benefit from rolling resistance and aerodynamics improvements.
"Mod #1: Front air dam.
They started by making & installing an air dam beneath the Pinto’s front bumper to divert as much air flow as possible away from the car’s aerodynamically dirty underside. That single change accounted for fully one quarter of their gains.
Mod #2: Partial grill block.
Another highly turbulent air pathway is the cooling system. Most cars’ grill openings are sized to keep the engine cool in absolute worst-case conditions (think Death Valley, pulling a trailer). By blocking part of the Pinto’s grill, they were able to improve efficiency without adversely affecting engine temperatures in normal driving.
Mod #3: Smoother tail (rear spoiler).
The aerodynamically ideal shape at the rear of a vehicle is a gradual taper that helps minimize the size of the turbulent wake left behind. But the slope of the Pinto’s rear window was too steep. By adding a six inch spoiler, they effectively changed the angle of air flow between the end of the roof and the back of the car. The result: a 7% MPG improvement.
Mod #4: Smoother nose.
While almost every new car sold today has a smoothly contoured front end, the Pinto’s face left a lot to be desired. To partly address this, they made and installed convex plexiglass covers over the car’s headlight buckets. That small change added 0.1 MPG.
Mod #5: Reduced parasitic loads.
Back in ‘74, most cars sported a belt-driven radiator fan. By removing two of the Pinto’s four fan blades, it was made more efficient. Today, most vehicles have electric cooling fans that run on demand only.
Mod #6: Reduced rolling resistance.
The stock Pinto came with bias-ply tires. Switching to steel belted radials netted a 5% MPG improvement. While all new cars today come with radial tires, LRR (Low Rolling Resistance) versions are available which offer an equivalent improvement over “standard” radials."
As you can see from this chart, we haven't made that much progress. It might seem like we have since most current economy cars get in the 30 miles per gallon range at 70 mph, but compared to other technologies, a 100% improvement in 34 years is horrible, even when you consider progress in other areas (safety, comfort, etc).
Thanks to Darin at EcoModder for the tip!
::$11 worth of mods plus new tires - Car and Driver improves MPG by 25%
See also: ::DIY AeroCivic: It's Ugly, But it Gets 95 Miles Per Gallon, ::The Canadian Driver Fuel Economy Challenge, ::Souped Down 1959 Opel T-1 Gets 376.59 mpg
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replace the prius hybrid electric system. Lose the weight, keep the aerodynamics. Install new 4cl diesel. Sell new Prius. I will buy. (same for Honda Civic).
Make the aero-kit an option for all civic models.
Amazing that with just some simple modifications you can improve gas mileage significantly. That's a great start, but what's the next step? What will be the best, next fuel source for all the cars being driven throughout the world? Anyone have an opinion on what's already out there that will come to the forefront? We here a lot about biodiesel, but it apparently creates problems of its own--like pesticide/herbicide/runoff pollution of waterways, redirection of farm land from food production, increased cost of wheat due to switching of production, etc.
What will be the next best solution for powering cars that is in line with environmental protection/improvement and yet allows us to maintain a semblance of our current lifestyle?
Unfortunately, most modern aero kits are for people who want to go fast, not people who want to save gas, and are styled appropriately.
Icelander: Yes aerodynamic body add-ons are designed for people with speed in mind but how do you increase speed? You reduce parasitic drag on the body of the car; therefore creating the same effect on gas mileage as the article states. You just need to keep driving like you do and not like the people the parts are really made for. Both people are looking for a slicker body to slide through the air easier. :~)
Why aren't cars more aerdynamic? Car ads often show the car in fancy wind tunnels, but this seems pretty ridiculous considering they're barely more aerodynamic than a T-bloody-Ford!
Fancy wind tunnels are mostly use for ads, actually..
If you saw the 95 mpg civic article, that fellow made a front air dam/spoiler, a slippery tail (think Auburn Boattail Speedster) and finally, he added fender skirts front and rear. Looked hideous to me, but looks are no longer very high on my priority list.
Here's a tip for improved fuel economy that is too often ignored though. Don't sit idling in the drive-thru line at McDonalds, the bank, etc. If you can park and go inside, do that. If that isn't an option, at least turn the engine off until it's time to move.
Here's another modification to improve gas milage:
Step 1: buy folding bike
Step 2: put folding bike in car trunk
Step 3: park in one spot when you're on the other side of town, take folding bike out of trunk and ride to all the places you need
Or is that cheating?
@Bill, the batteries in the Prius weigh just 100 lbs. Take out the batteries and motors, and you'll need to add a larger engine and fuel tank. All of which add weight right back into the vehicle.
Net weight loss: zero.
Plus, with no electric motors you lose the solar and PHEV options.
All this is just common sense, the exercise is to shift the mentalities of people who see a hybrid SUV returning 22mpg as an environmentally friendly alternative. We can't change people from wanting to drive that easily, but we could get them out of the thirsty V8s and V6s that litter the roas of America. Then if all else fails we should make it as popular to pay for a carbon offset via a group like http://www.carbonneutral.com rather than getting the smug "hybrid" license plate.
My brakes last my 325,000km. Not much regeneration going on here. I need a Honda Insight with a one liter diesel in it. It would be close to 100mpg car. By the way Marks talking maybe Honda should being it back. Until they get a good EV a person needs something to get around in.
"@Bill, the batteries in the Prius weigh just 100 lbs. Take out the batteries and motors, and you'll need to add a larger engine and fuel tank. All of which add weight right back into the vehicle.
Net weight loss: zero."
Actually, I doubt a larger engine would be needed, at most one tuned for slightly more torque at the low end.
A 55 HP 1.0L three cylinder was plenty for a Geo Metro, so the stock Prius engine looks OK on it's own.
Cindy,
next best solution..well steam engine, no no not the locomotive engine from 19th century. See the design of Cyclone Power Technologies
http://www.cyclonepower.com
Very interesting design.
Efficiency comparable to Diesel, emission much lower then any internal combustion engine, no transmission and clutch necessary, the torque is enormous , that significantly improve the efficiency - regular car get only 5-15% of total power to the wheel, this engine will get all 36% to the wheel. You can expect 2-3 time higher millage then most diesel. On the top of it steam engine to not have idle cycle - perfect for city driving. That not every thing. The engine very quiet.
Another idea
What can be done to improve internal combustion engine that are now in production?
Well there was some Romanian inventor George Constantinesco in 1920s that invented something coled inertia transmission. Thats continuously variable transmission.. absolutely ingenuous approach to solve the problem. One of the application was to build low cost car for the people that will make 100mpg.. well he did. One of the advantage was that it keep the engine in the best efficiency region. He ache linear torque power characteristic change with out using any computers (1920s) just pure mechanic. Just amazing. With inertia transmission you could down size the engine and still get the performance. The mileage will go up by 2-3 time
Here the link is somebody interested:
http://fluid.power.net/fpn/const/const005.html
There is a lot of new and old ideas that can and should be used.
Mark Thats good but if you live where i live the car would be stolen before you got back .
Long, you are wrong. prius battery is 150lbs alone. most hybrids add up to 300lbs. total. put the hybrid in corrolla and see small benefit to milage. hybrids lose value quicker than diesels. plugins are not good either since most electricity is coal. hybrids are like CFLs, just transitional technology. until better engines are developed, i like diesel, indeed.