
 Term          Contrast Estimate Std. Error     z Pr(>|z|)    5.0 %  95.0 %
  cyl mean(6) - mean(4)   -5.968     1.6393 -3.64   <0.001  -8.6640 -3.2713
  cyl mean(8) - mean(4)   -8.521     2.3261 -3.66   <0.001 -12.3469 -4.6948
  hp  mean(dY/dX)         -0.024     0.0154 -1.56    0.119  -0.0494  0.0013

Columns: term, contrast, estimate, std.error, statistic, p.value, conf.low, conf.high 

