"We have the best of both worlds. We are beholden to the Ministry of Education, but we get great support from the private sector."
He said schools already had a "good deal of autonomy" since the 1989 changes in the Tomorrow's Schools initiative.
He saw potential dangers in charter schools.
"If people have total control over the curriculum, that's open to go down a path which may or may not be beneficial for everyone. And I think performance pay for teachers is another area where it would make it harder for us to attract good staff."
But he said the money from Mainfreight had made a significant difference.
Could the school survive without it?
"Yes. Could we do as well as we do without it? No."
He said the school was not accountable to Mainfreight, and the company donated money on a case-by-case basis.
"We come up with a project we think is worthwhile and discuss it with Mainfreight."
In 2007, Mainfreight helped the school buy smartboards - interactive whiteboards.
"Instead of us taking four years to get them, we had them all in 2008."
In the past 10 years, Mainfreight had gifted the school about $750,000, he said. The school's annual budget was about $700,000.
In return the schools carries the company name, and the children's uniforms carry the Mainfreight logo.
"We try and make sure our kids, wherever they are, live up to the expectations that Mainfreight have or their staff - well dressed, approachable. Not only are they representing the school, but Mainfreight as well," Mr Lyth said.
He said he did not need more autonomy - though he could always use more money.