No, it doesn't significantly change the fuel through the injectors.

If you're paranoid, get a wide-band - check AFR's before and after running pre-mix...





-Ted

 

I agree. Even at a 20:1 mixture (which is WAAAY more oil than you would use), you're only taking 5% of your injector capacity. Hopefully, you've got more headroom than that. If not, then the injector upgrade is surely warranted regardless.



By all means, check the AFR's before and after. There is no substitute for peace of mind.