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Ecky · 04-20-2015, 09:45 AM

VTEC is essentially having two cam profiles optimized for different rev ranges, and usually the switchover is 4-5,000RPM. It wouldn't surprise me if most VTEC engines had better fuel economy (all else being equal) than their non-VTEC counterparts due to the lower-rev-range cam profile being tuned for lower revs, rather than aiming for the middle as is the case with a lot of Honda's non-VTEC designs.

As firehawk618 said, most VTEC engines (aside from the ones in the VX/HX models) are geared much shorter though, which probably accounts for most of the mileage differences.

04-20-2015, 09:45 AM	#8 (permalink)
Ecky Master EcoModder Join Date: Dec 2011 Location: New Zealand Posts: 5,117 ND Miata - '15 Mazda MX-5 Special Package 90 day: 39.72 mpg (US) Oxygen Blue - '00 Honda Insight 90 day: 59.69 mpg (US) Thanks: 2,914 Thanked 2,587 Times in 1,607 Posts	VTEC is essentially having two cam profiles optimized for different rev ranges, and usually the switchover is 4-5,000RPM. It wouldn't surprise me if most VTEC engines had better fuel economy (all else being equal) than their non-VTEC counterparts due to the lower-rev-range cam profile being tuned for lower revs, rather than aiming for the middle as is the case with a lot of Honda's non-VTEC designs. As firehawk618 said, most VTEC engines (aside from the ones in the VX/HX models) are geared much shorter though, which probably accounts for most of the mileage differences. __________________ Ecky's (new) JDM Insight Ecomodding 2015 MX-5 Miata Honda Insight w/Acura TSX engine 2000 Insight TLC & Build Thread Last edited by Ecky; 04-20-2015 at 10:10 AM..