View Single Post
Old 09-17-2019, 05:20 PM   #4 (permalink)
EcoModding Lurker
Join Date: May 2016
Location: Virginia
Posts: 27
Thanks: 0
Thanked 11 Times in 9 Posts
Originally Posted by roosterk0031 View Post
Best example for #1 I know of is the 2016 to 2017 Elantra, 2016 was a 1.8 liter (147 hp, 10.3:1 compression ratio) with automatic ratings of 28/37/31, 2017 they changed the stroke to make it a 2.0 and Atkinson it and makes the about the same hp/tq with 12.5:1 compression ratio and MPG ratings up to 29/38/33.

I got 49 mpg over 200 miles in my 17 Elantra just setting cruise at 57 or so.

I don't think Atkinson a diesel does any good, diesel don't run at a fixed air to fuel ratio, the reason to Atkinson a gas it is so the engine doesn't get a full cylinder of air it without having to choke it with the throttle. The above it port injected so it actually pushed some fuel/air mix back into the intake during the beginning of the combustion stroke.

From my understanding , it's not a fuel mixture or air ratio thing that gives the atkinson engine its added efficiency but rather the added energy extraction from an effectively reduced intake charge stroke VS the longer power stroke.

I have looked into a custom camshaft earlier today and hopefully they'll be able to brew one up (long live Benedict Arnold Prius !!) ;-)

2003 Jetta TDI Wagon, 5 sp, 210K miles, Stock.....for now!
  Reply With Quote