At any rate, some of our online friends observed that certain brands of fuel give better mileage than others. Take note though that higher Octane ratings are not indicators of good mileage. So what do we look for in our fuel?

What to look for in choosing your fuel

1. Stay away from reformulated fuel.
2. If you can get btu information, pick a gasoline with higher btu.
3. Clean burning fuels mean less waste.
4. If all else fails, stick with normal unleaded fuel (ethanol mixes may be greener but they give lower mileage, special fuels like Shell’s Velocity tend to give less mileage than their regular unleaded fuel varieties).

I have thought out - at great length - about the first mod I would add to my car. I didn’t want to announce to all and sundry that I was modding my car but wanted to get the most bang for my buck in stretching my car’s fuel economy. After a couple of forum visits, some car shop visits and a bit of research I decided on adding a racing air filter.

Some would ask why add a racing filter if you wouldn’t be racing. But the theoreticals are safe - you add more air to the fuel air mixture and the fuel vapors are better spread out, thus optimizing combustion. This results in better combustion, ergo more power/torque and a cleaner engine.

For more info on intake systems you can visit one of these top 3 intake makers:

• Apexi
• K & N
• Simota

The review:

I wanted the Apexi intake as all the experts I consulted told me that they were the absolute best performance-wise. However, their price is quite the deterrent as their intake solutions cost almost 6 to 7 times the cheapest solution.

K & N comes in 2nd for quality but their price and maintenance costs are very restrictive. They cost less than Apexi but you need to clean them with a special oil solution that they provide. On top of that, they cost twice more than Simota ones.

Simota are the most economical of the three. It’s price and cheap maintenance make it a winner for people in my income bracket. And according to Simota users, they still give great performance returns. So I went with a Simota racing filter.

The results:

From my worst mileage of 18 mpg or 8 kpl (while running against the wind on the highway, going through flood and some medium to heavy traffic) I went up to 25 mpg or 10.5 kpl (running against the wind, floods, and with 4 passengers + 6 bags of groceries ~ 750 lbs or 340 kg worth of weight, aaaand roughly 3 hours of traffic).

I used to average 25 mpg or 11 kpl in combined city and highway driving (with most of my driving in city settings). Nowadays I average a nice 30 mpg or 13 kpl.

My best score of 33 mpg or 14 kpl is still my top score though, as I have yet to drive on a sunny day with nearly no traffic.

Of course these are Simota gains, so I wouldn’t know how well an Apexi or K&N filter would fare. Unless someone sends me a cone type filter for both (hint, hint) :grins:

Oh btw, if you are a reader from North America you can get great deals on cold air intakes if you click here
.

That is as bad as it gets in the field of fuel economy. 16 mpg is roughly as costly as driving your all-american SUV from GMC or Ford (the non-hybrid ones).

Nowadays I average 26 mpg (11 kpl) on a bad day - driving at night and against the wind. My top “score” was 33 mpg (14 kpl).

Hopefully, after reading that my TV antenna can be forgiven?

Also, I drove recently (100% city night driving and some traffic) with a head-on wind, floods and 3 passengers to my worst mpg yet since I started hypermiling: ~20 mpg (~9 kpl). Proof positive that bad winds, and overrevving your engine (so that floodwater does not enter your exhaust) will kill all hope for any kind of hypermiling. Drive safe everyone!

Update (9/25/2008): While driving in 3 hours worth of traffic and mostly city driving, plus around 750 lbs or 340 kg of people and groceries (4 passengers and about 6 bags of groceries) - whilst going through some rain, flood and a tailwind, I registered around 25 mpg (10.6 kpl) - not bad.

So what is DWB? Driving without breaks is actually driving as if you did not have brakes. Meaning its a mental shift into thinking that you do not have the means to stop your car on a dime.

So what does that mean?

• You scan the road further ahead for possible events and obstructions that will affect your driving
• You slow down by letting go of the gas pedal and shifting the transmission to neutral
• You observe very safe following distances (4 seconds away from the vehicle in front of you)
• You observe speed limits (both minimum and maximum ends of the spectrum)
• You slow down farther away than normal so you can glide to a stop naturally
• You slow down waaaay before a traffic light red, because “you don’t have brakes”

Hmmmm. How does that affect my fuel economy? I don’t see how it helps me achieve the best mpg for my car.

It helps in several ways.

1. Driving slowly (because “you don’t have brakes”) will help you achieve better mileage.
2. Braking uses energy to stop the car. This is energy that you pay for in terms of fuel. On top of that, the energy you counter (the forward motion of the vehicle) was also paid for in terms of fuel. That means you use up fuel to stop the vehicle that you used fuel on to move in the first place.
3. Accelerating after braking to a standstill uses up more fuel than accelerating from a coast.
4. Slowing down before a red light, will lessen the time you spend idling at that stop.

That’s all for now, safe hypermiling everyone!

Actually, ALL hypermilers want it hot. No, not that kind of hot (takes out the images of near naked bodies on the beach from your mind).

We are talking about hypermiling here. So when I say hot, I mean temperature.

Temperature is a big factor in hypermiling, as there is a certain temperature that the engine has to reach before achieving maximum efficiency.

On top of that, vaporized gasoline burns more efficiently as there is more surface area exposed to the spark plugs.

Another plus factor is that if you drive in a rural area - lunchtime (the hottest time of the day) is most often the least congested time on the road. Thus, allowing for full implementation of your hypermiling techniques without any danger of inciting road rage or of having another driver affect how you hypermile your way into your best mpg.

The only time a hypermiler avoids hotter temperatures is when they gas up. It does not affect how much gas you put in the tank (that is a myth) because gas pump temperatures remain somewhere around 62F (16C) in most states. But rather, you lose a precious few more drops of gas when you open the gas tank and gasoline vapor escapes - because there is simply more fuel vapor when its hotter.

In a nutshell: Drive when its hot. Gas up when its not.

PAG/PAC (Pulse and Glide/Punch and Coast) is a modified FAS.  The first step to implementing it is to find a suitably straight and decently paved stretch of highway. Then do the following:

1. Set a top and minimum speed that you want to maintain. Personally , I use 50-40 mph (80-60 kph).
2. Accelerate to reach your set top speed.
3. Coast. You can either put the tranny in neutral, or cut off the engine entirely.
4. When you begin decelerating to your minimum speed, re-engage the engine.
5. If you killed the engine, you will need to pushstart it:Shift the gear to match the speed push the clutch down.
   10-19 kph (6-11 mph) - 1st gear
   20-39 kph (12-24 mph) - 2nd gear
   40-59 kph (25-36 mph) - 3rd gear
   60-79 kph (37-49 mph) - 4th gear
   80 kph (50 mph) - onwards - 5th gear
   Quickly release clutch and step on gas until motor starts.
6. If you kept the engine on, match the speed to the gear and shift into the correct gear:10-19 kph (6-11 mph) - 1st gear
   20-39 kph (12-24 mph) - 2nd gear
   40-59 kph (25-36 mph) - 3rd gear
   60-79 kph (37-49 mph) - 4th gear
   80 kph (50 mph) - onwards - 5th gear
7. Repeat the process ad infinitum ad nauseaum.

Obviously, being a modified Forced Auto Stop it carries the same caveats and disadvantages as the original technique. Please read our FAS article here to learn more about the original technique before you try this one.

WARNING! Do not try this with automatic transmission vehicles or ones with VVT.

As they go around you, they create a low pressure zone across the entire roadway called the traffic-side draft.  When coasting with the engine off, this low pressure area will give you a 15 to 20 second boost as it sucks you along.

So in a nutshell, this is how you do this technique:

1. On the highway, stay on the rightmost lane.
2. Follow the posted speed limits. Halfway between minimum and maximum posted limits work best.
3. Start to coast when the opportunity presents itself (I personally coast with the engine on by putting the car in neutral, others turn the engine off).
4. Enjoy the benefits of the traffic-side drift as the cars zoom around you.

This is the only publicly recommended technique by Wayne Gerdes the father of hypermiling.

My jaw dropped and so did my heart. I was appalled at how much ignorance showed not only in the comments to it but in the main article itself. People not interested in the following rant can skip the parts marked out as such.

<Start of RANT>

The generalization that hypermiling is illegal and risky is just plain naive and ignorant. Sure some techniques advocated by hypermiling die-hards are illegal and risky: stuff like tail-gaiting, shutting off engines during a FAS, etc.

But what about going below max speed limits? Planning trips? Keeping your foot light on the gas pedal? Travelling light? There is nothing wrong with those - a large number of hypermiling techniques advocate safe following distances (so that you don’t brake often), observing speed limits, defensive driving techniques, etc.

I hope the people at CBN (and the ignorant police officer) learn more about hypermilers before actually generalizing and branding all of us crooks. That is like saying that all hackers are criminals … but then thats a story for another blog and another time.

<End of RANT>

What is the FAS (Forced Auto Stop)?
It’s the technique were you use the situation to enable your vehicle to move continuously with the engine off. Move with the engine off? Right. You use gravity as in the case of a downhill road, pockets of quasi-vacuum left behind by trailers or big buses on the highway that will suck you in, and good old momentum.

Personally, though I do not suggest killing the engine when driving. This is way too dangerous. With the engine off, your brakes and steering capabilities are compromised and you will have to push-start your engine back on. This will take its toll on your engine and parts.

I drive a Mitsubishi Lancer with manual transmission, so I use a modified version where I have the transmission in neutral but the engine stays on. That way, brakes and steering are running 100% but the engine is idling at 700 rpms instead of my usual 1800-2000 rpms. This allows me about 10% fuel savings in terms of mpg/kpl. (This is also the technique I employ when doing the pulse and glide - more on this later.)

What cars are best for FAS?
On the outtake, I would suggest that manual transmission conventional vehicles are more suited to FAS. But hybrids have been known to do AS (Auto Stop) better.

How to do a FAS using a manual transmission vehicle (don’t do FAS on auto trannies and CVTs)

1. Evaluate the situation
   1. Do you have cars too close behind you that could bump into you if you execute a FAS? Roadrage is another danger too if you have cars behind you.
   2. Are there possible obstructions up ahead that will endanger you and your passengers if you FAS?
   3. Is there an opportunity to FAS?When the conditions are right, put the car in neutral and coast. At this point, killing the engine is optional (but a very dangerous option).
      1. Downhill?
      2. Trailer truck/bus up ahead? Always remember to observe safe following distances!!!
      3. Running fast enough (around 50 mph [80 kph])?
   4. If you killed the engine, you will need to pushstart it:
      1. Shift the gear to match the speed push the clutch down.
         10-19 kph (6-11 mph) - 1st gear
         20-39 kph (12-24 mph) - 2nd gear
         40-59 kph (25-36 mph) - 3rd gear
         60-79 kph (37-49 mph) - 4th gear
         80 kph (50 mph) - onwards - 5th gear
      2. Quickly release clutch and step on gas until motor starts.
   5. If you kept the engine on, match the speed to the gear and shift into the correct gear:
      10-19 kph (6-11 mph) - 1st gear
      20-39 kph (12-24 mph) - 2nd gear
      40-59 kph (25-36 mph) - 3rd gear
      60-79 kph (37-49 mph) - 4th gear
      80 kph (50 mph) - onwards - 5th gear

Disadvantages of FAS
FAS is great for manual transmission vehicles, but you need to match the speed to your gear when resuming acceleration after an auto stop. Not doing so will shorten the lifespan of your transmission gears and clutch gears (slow engine + fast transmission gears = detonated clutch). Failure to match speed to gear will result in locking up your wheels. Thus, you lose control in those few moments - not something you want happening on a slippery highway.

If you turn off the engine during a FAS, there is also the off-chance that the car wil not restart (mechanical/electrical issues not enough momentum to pushstart again, etc.)

Another con is that automatic transmission cars will experience transmission and clutch degredation shortening the lifespan of these said parts. Cars with CVT (continuously variale transmission) would not act favorably to the engage-release cycle that you do as well.

Advantage of FAS
Fuel economy (as per my experience, I recorded an average 10% savings)

How to FAS using a hybrid vehicle
Set the autostop setting (consult your car manual).
Drive to meet the FAS conditions, then let go of the accelerator.

There are three factors in tires that affect your cars best mpg:
1. Pressure
2. Cleanliness
3. Maintenance

Pressure. The higher the pressure, the lower the rolling friction - resulting in better mileage. The suggested tire pressure can be seen in the owner’s manual or on a placard on the end of the driver’s side door (sometimes inside the glove compartment) — this is the minimum pressure you should set your tires to.

Wayne Gerdes actually recommends going for the max sidewall pressure listed on your tirewall, although he cautions that you shouldn’t go higher than 25% of that value as there are legal limits to these things.

On the plus side, you get better mileage, lower thread wear, more even threadwear across thread widths, better handling (sometimes) and shorter braking distances in some situations. However, your tires become noisy, vibrate more and you get a harsher ride.

Cleanliness. Yes, one should clean their tires. Mud, small rocks, gravel or whathaveyou stuck in between the threads will aversely affect your tire’s grip. Slipping tires translate to loss of kinetic energy that should have been translated into your car’s forward motion and directly translates to loss of fuel economy.

Maintenance. One should also maintain their tires, as poorly maintained tires lower your fuel economy by a significant amount (personal experience is along 30%).

Tire maintenance made simple

1. Maintain proper air pressure. Check air pressure once a month, because normal air loss is 1 psi per month
   Vehicle manufacturers list recommended tire pressures for original vehicle tires in the owner’s manual or on a placard on the end of the driver’s side door or in the glove box. An underinflated tire has more friction with the ground - this translates to more heat, damaging the tires and more fuel consumption. A grossly overinflated tire will have uneven threadwear, which will also damage the tires. So be sure to fill them up just right.Use the recommended tire pressure and vary only slightly depending on temperature and load conditions (colder temps and/or bigger loads = bigger pressure). As a rule of thumb, each 10°F (12°C) change in outside temperature causes a 1 psi change internally in the tire.
2. Rotate every 8,000 km (~5,000 mi)A. If driving a 4WD or rear wheel drive vehicle, rotation should go:
   a. Left front wheel to right rear position.
   b. Right front wheel to left rear position.
   c. Left rear wheel to left front position.
   d. Right rear wheel to right front position.B. If Driving a front wheel drive vehicle, rotation should be:
   a. Left front wheel to left rear position.
   b. Right front wheel to right rear position.
   c. Left rear wheel to right front position.
   d. Right rear wheel to left front position.  
3. Evaluate your tires everyday for threadwear and sidewall damage.
   • Expose thread bars are for replacement
   • Irregular wear are for camber and/or toe-in toe-out inspection
   • Tires with less than 2.1 mm (from a top of a penny to the top of Lincoln’s head if you want to measure it that way, just insert a penny into the thread - if the top of Lincoln’s head shows then it’s time to change tires)

For readers residing in the good ole’ USA you can get great tire discounts on quality branded tires here.