The phrase "a substantial difference to" is correct and usable in written English.
It can be used when discussing the impact or effect that something has on another thing, often in a comparative context.
Example: "The new policy made a substantial difference to employee morale and productivity."
Alternatives: "a significant impact on" or "a considerable effect on".
The development "will make a substantial difference to the shortfall in London," he added.
It could make a substantial difference to some middle-class families.
There is no benefit in 'salami-slicing' and spreading the funds too thinly to make a substantial difference to anyone.
Tinsley is also wary about believing that the EBacc will make a substantial difference to language learning.
Having direct access to open space - a balcony, terrace or roof area - makes a substantial difference to the quality of everyday life.
Though the higher prices can be a moderate nuisance to real estate businesses or home buyers, they have made a substantial difference to the county budget.
He found that, like people everywhere, they had difficulties resisting the temptation to spend what little they had, even when they recognised that it would be better to save for a goal that could make a more substantial difference to their lives.
The computational results highlighted that changing the bridging length made a more substantial difference to the stiffness and fracture movement than varying other parameters.
Second, the way in which contacts are weighted or defined makes a very substantial difference to quantification of R0 and its components.
The average of all scores stayed the same across the years, but individual IQ scores rose or fell by as many as 21 points, a substantial difference – enough to take a person of "average" intelligence to "gifted" status, or vice versa.
A substantial difference, according to two out of the three court of appeal judges.
