Improving Hybrid Car Gas Mileage - How I got over 58 mpg from my TCH
In order to help you offset the high cost of gas, I wrote an article on how you can save money on gas. In 2007, the article became very popular due to the higher cost of oil. Now we are heading back in this direction and we may eventually surpass those levels as the economy rebounds.
I took advantage of the low cost period and replaced my cars with hybrids. Most of the tips in the previous extensive article are valid for hybrid drivers as well. I highly recommend that you read them too in order to maximize your potential. Those tips will teach you how to drive with efficiency in mind.
In this new article, I will include more techniques that are mostly beneficial for hybrid owners. Those are additional tips that helped me push my Toyota Camry Hybrid (TCH) to get 58.2 mpg. Since this was a winter drive and fuel efficiency in hybrids is always better in summer, I expect to push this number even higher.
Warm up period
Today’s Hybrids need a minimum engine temperature before they can shut off the engine. During this time, the timing of the engine is also different, to help the engine warm up faster. Unfortunately, this means also higher fuel consumption. Simply put, the first minutes of the drive are the worst in terms of fuel.
1. Learn to combine several short trips. Ask everyone else in the family if they need anything. Make a grocery list and learn to manage your stock, so that you have more flexibility on when to go shopping. Do not let your car cool off between trips, park in a garage if you can! Savings potential: 10% - 50%
2. Consider installing an engine block heater. This device installs to your car and pre-heats your engine block from the electrical outlet. Your hybrid will go into EV (electric vehicle) mode faster, letting you skip the warm up period. Savings potential: 5% - 40%
3. If the outside temperature drops, I (partially) block my front grille. I determine the amount of blockage empirically, trying to find the right balance by avoiding the engine fan from running (coolant temperature getting too hot) while ensuring a faster startup. I usually do not block anything above 45-50˚F (7-13˚C) and I fully block the grille below 0˚F (-18˚C). Only do this if you are comfortable blocking the grille and if you can remember removing the blockage when the outside air temperature increases. Savings potential: 0% - 15%
In this image, you can see some of the foam I put between the openings of my grille in order to block about 25% of the cold air.
4. If your car computer does not show coolant temperature, get a better gauge like the Ultragauge or Scangauge. Keep your coolant temperature below 194˚F (90˚C) and remove blockage if it goes above. You can use your gauge to monitor other vitals as well, like RPM, engine temperature, and, in case of the Scangauge, even the battery level (State of Charge). Make sure they support your car. Savings potential: 0% - 15%. This can prevent damage and help you optimize your mpg strategy.
The parallel hybrid and two-mode hybrid drive-trains have the capability to drive with battery only. Toyota, Nissan, Mercedes, and Chevrolet use this technique. The series hybrid drive-trains of Honda and Saturn have very limited or no EV mode capabilities.
how your car gets into and out of EV mode! Savings potential: 0% - 10%
car is different and how it behaves will have an influence on your technique.
your battery charge! Savings potential: 0% - 5%
8. I do always try to stay in EV mode as long as possible before turning the car off. When I am looking for a parking spot in a garage, or on the last mile home, I carefully coast with EV. The car will go through a warm up period when I start it anyways, which will replenish my charge. Savings potential: 1% - 2%
aware driving. Savings potential: 0% - 10%
(My Escape at Teakettle Junction)
10. Sometimes I keep my downhill speed just below or at 40mph in the Toyota. This way my engine is off and I charge the battery. Above 40, the engine will be on. If I do not press the gas, the computer will cut the fuel to the engine, but additional friction makes it less efficient. I only do this if the speed limit is 40mph to avoid annoying others. Savings potential: 0% - 5%
Traffic Timing and Shifting
11. Pay attention to the traffic ahead of you. If the light has turned red, there is no need to mash the gas pedal and let your combustion engine start. Coast to the red light instead! This seems to tick off some people. Just stay calm. Savings potential: 5% - 10%
12. If the green light ahead of you is stale, it will most likely turn red before you get there. A stale light is a light that has been green for some time, with no cars entering the intersection from your side, thus not tripping the sensors. There is no need to rush if you are still far away. Start to coast instead! Savings potential: 0% - 3%
13. Use other cars to trip the traffic light sensors. I have no desire to arrive first at a red traffic light. I let other drivers race ahead and stand on the induction sensors. This will cause the traffic light to switch, hopefully before I get there. You can learn the timing of the traffic lights on your route and avoid some stops completely. Savings potential: 0% - 2%
14. Avoid jackrabbit starts, but do not stall out people behind you. It is more fuel efficient to accelerate normally, lift the foot from the gas, and feather it lightly. Either your car will go to EV mode quicker, or the CV transmission (common in hybrid cars) will go to a very high (and thus efficient) transmission ratio very quickly. Savings potential: 2% - 10%
15. Understand how the CV transmission
works! Savings potential: 5% - 10%
16. Do not use the cruise
Hybrid cars recapture energy that you lose when you break. The electric generators transform mechanical energy into electric energy that they store in the batteries. They take their mechanical energy from the rotation of the wheels, thus slowing the car down.
The power that the generator creates is equivalent to P=torque x speed, where the torque is your braking force (how hard you mash the pedal). Due to internal losses, generators aren’t the most efficient at their absolute maximum rating. Additionally, you incur electric losses due to the resistivity of the power bus. Further, batteries have a greater capacity to accept charge when they are nearly empty compared to nearly full batteries.
You do not need to remember the technical details, since I will translate them into driving recommendations for you.
17. Use your battery level indicator if you have one. Try to keep your battery within the sweet spot, not too full if you anticipate that you will break a few times. This maximizes your capacity to recapture all the energy you can. Burn off excess capacity by keeping your car in EV mode longer. Savings potential: 0% - 10%
18. Anticipate the traffic ahead and brake early to avoid hard braking. If you brake very hard, the “normal” brakes will engage, wasting all that energy. Even if the friction brakes don’t engage, you will generate more current and thus incur more losses in the system. Savings potential: 5% - 10%
19. Avoid full stops and try to stay in motion as much as possible. If you approach a stop light, try to slow down earlier. I hope that the light will turn before I get there. Most hybrid cars cannot capture braking energy below a certain speed (7mph for the Escape). Savings potential: 0% - 5%
Car Maintenance and Fuel
20. I tested expensive gasoline (top tier gas) against cheap brands on thousands of miles of road and could not notice an appreciative difference. My best mpg run so far (58.2mpg) was after a fill up at a discount super market gas station. Savings potential: 10ct/gal
21. Many people claim that synthetic oil gives you a better mileage. I believe that too, but it hurts my goal of achieving the best dollar/mileage ratio. The amount of gas you safe will not compensate for the higher cost of oil change. Choose the lowest viscosity oil with a price premium of no more than $10 above the regular oil! If your oil change intervals are longer (e.g. the Camry has 10k intervals), you can spend $20 more. Savings potential: $40
22. Inflate your tires and
check them regularly. I prefer a pressure above the recommendation of the
manufacturer. My Toyota calls for 32psi, yet the tires have a maximum pressure
rating of 44psi. All tires should have their maximum rated pressure indicated
on the side.
23. Choose a slightly different route home to see if you can improve your numbers. Don’t lose sight of the real prize, money spent. Sometimes you can find a longer route that gives you better fuel economy, but because it is longer, you will burn more gas. Savings potential: 0% - 10%
24. Keep a mileage log and notice when you get gas or what your internal gas gauge tells you. This way, you can look for patterns to identify the most efficient route. Alternate the routes ever day and evaluate your data after two months to reduce noise (temperature, abnormal congestion). Savings potential: 0% - 5%
25. I often back into a parking spot. Since you park at the end of your drive, you will normally be in EV mode, but when you drive out of your spot, you will be running the engine. Since I want to use the energy to drive forward instead of idling while backing out, I back into parking spots. Savings potential: 0% - 1%
26. Turn off the air
27. Slow down! Speed reduces fuel economy exponentially. Driving fast makes a surprisingly small difference in time you spend on the road, but a larger difference in fuel you pump through your engine. Savings potential: 10% - 40%
Advanced Hybrid driving techniques
28. Many Prius owners
swear by the Pulse and Glide technique. It works, but it requires work
and may take some joy away from your commute.
29. I usually adapt the
Pulse and Glide technique to the terrain and to the traffic situation.
Sometimes it makes more sense to stay in glide mode longer, even using battery
charge to do this. After all that is what hybrid cars do best.
30. Avoid getting too excited about other drivers! Although this is not a hybrid tactic, it still applies and it is very difficult. Others always seem to behave stupidly. They seem to be doing everything they can to upset you. If you lose your cool, you will not be in the best frame of mind to save gas. You probably will not even care. Take a deep breath and remember that your anger hurts only you and your fuel efficiency. The other driver is completely oblivious to your agony. Choose not to hurt yourself!
31. Drafting is extremely dangerous and inadvisable. It could also damage your windshield, due to stones thrown from the vehicle that you draft. I am not drafting anymore, but it works exceptionally well in hybrid cars due to their CV transmission. The reduction in drag will let the transmission shift to a very high gear ratio (higher than regular cars) and you can watch your mileage drop instantly. Some truck drivers may react very annoyed. I was able to achieve my numbers without drafting. Savings potential: 5% - 30%
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