Tests run slower with Maven than with IDE

I'm facing some test time execution issue related to local test execution with Maven. I have around 250 tests which run about 15 min on the IDE test runner and about an hour (55min to be exact) when executing them with maven locally. I tried a lot of configurations to make test execution in parallel but neither of them work for me, the time is still the same...probably I'm doing something wrong. Can anyone help on this? The last maven surefire plugin configuration that I tried is the following:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.19.1</version>
    <configuration>
      <parallel>methods</parallel>
      <threadCount>10</threadCount>
    </configuration>
  </plugin>

And for test execution command I've used:

• mvn test
• mvn surefire:test