Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - City driving econ: Faster accel in lower gears vs. Slower accel in higher gears?

Ankleface · 08-27-2024, 10:27 AM

Hi there cRiPpLe_rOoStEr, thanks a lot for your reply as well.

The previous car I mentioned was a Toyota Corolla with a 1.6L 4-cyl that I owned 20 years ago. And now I have a Hyundai i10 with 1.0L 3-cyl. I guess that was sort of an apples-to-oranges comparison because the two vehicles are not really very comparable. And the area where I used to drive the Toyota was a more spread-out city with less congestion and higher average speeds. I mainly mentioned that example because I've always been pretty conscientious about efficient driving, and my method of "accelerate briskly to the highest possible gear" worked effortlessly in the Corolla to get much better city consumption than the official rating.

You mention a good point about the displacement not being the only factor that affects fuel economy, I've definitely seen that too in other cars. But that's one of the reasons why I'm a bit confused about the high city consumption that I'm seeing now, because in my normal routes around town I never get anywhere close to the 100 KPH speeds where the final drive ratio would start to make a big difference. The Hyundai i10 was built primarily as a city car, and the gear ratios feel about right for that purpose, whereas on motorways it revs well over 3000 RPM at 100 KPH or above. Despite that it still has good consumption at those higher speeds even though it definitely feels out of sorts, whereas in the city environment where it was mainly designed to perform it's relatively thirsty. Going back to the example of the Corolla, that one didn't have a tachometer but it also sounded very revvy on the motorway. I assume that its sedan/saloon design would have been more aerodynamic at higher speeds compared to the Hyundai's relatively tall hatchback design, but at very low city speeds generally under 50 KPH aerodynamics shouldn't play a major role.

So again I realize that the two cars aren't really comparable, and the area where I drive most of the time now is different. I'm not sure about the power-to-weight ratio, based on acceleration I think it was probably better in the Corolla with its ~100 HP and ~135 Nm of torque, while the i10 only has like 65 HP and less than 100 Nm. The Corolla was more of a general purpose car with a fairly normally displacement, whereas the Hyundai i10 has one of the smallest engines currently available in a car. So that's why I feel like there must be some kind of optimization needed in my driving style now for the Hyundai. I'm not a habitual speeder, but I also don't like to go slower than everyone else just to save fuel. I've always accelerated fairly briskly to get out of the inefficient gears, and I anticipate red lights.

Sorry for the wall of text. ;-) Appreciate the replies.

08-27-2024, 10:27 AM	#6 (permalink)
Ankleface EcoModding Lurker Join Date: Aug 2024 Location: Planet Earth Posts: 8 Thanks: 7 Thanked 2 Times in 1 Post	Hi there cRiPpLe_rOoStEr, thanks a lot for your reply as well. The previous car I mentioned was a Toyota Corolla with a 1.6L 4-cyl that I owned 20 years ago. And now I have a Hyundai i10 with 1.0L 3-cyl. I guess that was sort of an apples-to-oranges comparison because the two vehicles are not really very comparable. And the area where I used to drive the Toyota was a more spread-out city with less congestion and higher average speeds. I mainly mentioned that example because I've always been pretty conscientious about efficient driving, and my method of "accelerate briskly to the highest possible gear" worked effortlessly in the Corolla to get much better city consumption than the official rating. You mention a good point about the displacement not being the only factor that affects fuel economy, I've definitely seen that too in other cars. But that's one of the reasons why I'm a bit confused about the high city consumption that I'm seeing now, because in my normal routes around town I never get anywhere close to the 100 KPH speeds where the final drive ratio would start to make a big difference. The Hyundai i10 was built primarily as a city car, and the gear ratios feel about right for that purpose, whereas on motorways it revs well over 3000 RPM at 100 KPH or above. Despite that it still has good consumption at those higher speeds even though it definitely feels out of sorts, whereas in the city environment where it was mainly designed to perform it's relatively thirsty. Going back to the example of the Corolla, that one didn't have a tachometer but it also sounded very revvy on the motorway. I assume that its sedan/saloon design would have been more aerodynamic at higher speeds compared to the Hyundai's relatively tall hatchback design, but at very low city speeds generally under 50 KPH aerodynamics shouldn't play a major role. So again I realize that the two cars aren't really comparable, and the area where I drive most of the time now is different. I'm not sure about the power-to-weight ratio, based on acceleration I think it was probably better in the Corolla with its ~100 HP and ~135 Nm of torque, while the i10 only has like 65 HP and less than 100 Nm. The Corolla was more of a general purpose car with a fairly normally displacement, whereas the Hyundai i10 has one of the smallest engines currently available in a car. So that's why I feel like there must be some kind of optimization needed in my driving style now for the Hyundai. I'm not a habitual speeder, but I also don't like to go slower than everyone else just to save fuel. I've always accelerated fairly briskly to get out of the inefficient gears, and I anticipate red lights. Sorry for the wall of text. ;-) Appreciate the replies.