backtop


Print 65 comment(s) - last by superstition.. on Oct 19 at 12:54 AM

Larger displacement Atkinson cycle engines may be in the future for Toyota

A number of automotive manufacturers have begun to move away from larger displacement naturally aspirated engines to smaller displacement turbocharged engines. The general idea was that smaller and lighter engines would use less fuel while offering the same sort of performance thanks to the addition of a turbocharger. However, in the real world many drivers have discovered that turbocharged small displacement engines are often unable to deliver on their fuel efficiency claims.

Toyota is considering bucking the industry trend and rather than going with smaller turbocharged engines, is considering larger naturally aspirated engines to improve fuel efficiency. Senior managing officer in charge of drivetrain R&D for Toyota Koei Saga recently said that Toyota believes gasoline engines could benefit more from upsizing capacity in conjunction with Atkinson combustion cycles than going smaller with turbochargers.
 
Atkinson engines today are typically only used in hybrid vehicles like the Prius, Ford Fusion Hybrid, Hyundai Sonata Hybrid, and Honda Accord Hybrid.


Toyota Camry
 
Increasing the displacement of an engine using the Atkinson cycle would deliver a specific output less than that of similarly sized conventional combustion cycle engines, but fuel economy would be better. Toyota believes that fuel economy would be better than the smaller engines they replace.
 
Toyota has offered no timeframe for bringing larger displacement Atkinson cycle engines to market and hasn't hinted at which models might get the Atkinson cycle engines.
 
Mazda experimented with similar “delayed valve” Miller Cycle technology over a decade ago in the Millenia midsize sedan. But instead of using electric motors to make up for the reduced power density like today’s Atkinson-engine hybrid vehicles, the Millenia used a supercharger.
 
Saga also talked a bit about the next generation Toyota Prius saying that the vehicle will use a mixture of battery technology including lithium-ion and nickel batteries. The reason for mixing battery types is that lithium-ion batteries are better for performance, but the durability and lifespan is better for nickel batteries. 

Source: Green Car Reports



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: According to whom?
By Spuke on 10/17/2013 3:58:57 PM , Rating: 2
quote:
one thing i see all the time that is a total waste of gas is people accelerating towards a red light
I thought I was the only one that noticed that. I see this crap ALL of the time. And what's up with the continuous acceleration between two points? There's a long stretch of road on my commute that starts at a stop sign and goes past a freeway entrance (about 6 miles). Most people turn onto the freeway. At LEAST 90% of the people I follow on this stretch accelerate the ENTIRE section, hitting their fastest speed on the last 1/3, then slow for the onramp. WTF is that?! No wonder most people can't match EPA mpg ratings.


"The whole principle [of censorship] is wrong. It's like demanding that grown men live on skim milk because the baby can't have steak." -- Robert Heinlein














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki