Jetboy
New member
The boost effectively shortens the power stroke as compared to the intake air volume. Thermal efficiency goes down in that scenario in most cases. Hence the reason atkinson cycle is more thermally efficient. You can try to solve the issue with a lean burn and cool the cyl. temps with direct injection - but we don't have that option. I would expect thermal efficiency to drop under most scenarios. The 1GR in a 4runner does not run at low output at highway speeds. It will probably be in boost range 95% of the time on the highway. I doubt it will experience a bypass condition very often.
I think it may see some improvements by not down shifting so often. I'd guess Magnusson also tunes it leaner than Toyota. I'm not sure how the ultimate balance works out. I would expect an mpg hit for most uses other than possibly towing where you're often in 3rd gear at high rpms. In that case staying in 5th gear might make up for the less efficient burn.
I think it may see some improvements by not down shifting so often. I'd guess Magnusson also tunes it leaner than Toyota. I'm not sure how the ultimate balance works out. I would expect an mpg hit for most uses other than possibly towing where you're often in 3rd gear at high rpms. In that case staying in 5th gear might make up for the less efficient burn.
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