diff --git a/sky130/openlane/sky130_fd_sc_hd/config.tcl b/sky130/openlane/sky130_fd_sc_hd/config.tcl
index a025650..5265875 100755
--- a/sky130/openlane/sky130_fd_sc_hd/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_hd/config.tcl
@@ -65,5 +65,7 @@
 set ::env(CLK_BUFFER_INPUT) A
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_hd__clkbuf_1 sky130_fd_sc_hd__clkbuf_2 sky130_fd_sc_hd__clkbuf_4 sky130_fd_sc_hd__clkbuf_8"
-set ::env(CTS_MAX_CAP) 1.53169
 set ::env(FP_PDN_RAIL_WIDTH) 0.48
+# Determined from https://github.com/google/skywater-pdk-libs-sky130_fd_sc_hd/blob/ac7fb61f06e6470b94e8afdf7c25268f62fbd7b1/cells/clkbuf/sky130_fd_sc_hd__clkbuf_16__tt_025C_1v80.lib.json
+set ::env(CTS_MAX_CAP) 1.53169
+set ::env(DEFAULT_MAX_TRAN) 0.75
diff --git a/sky130/openlane/sky130_fd_sc_hdll/config.tcl b/sky130/openlane/sky130_fd_sc_hdll/config.tcl
index cedfce9..b77b5cb 100755
--- a/sky130/openlane/sky130_fd_sc_hdll/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_hdll/config.tcl
@@ -62,5 +62,7 @@
 set ::env(CLK_BUFFER_INPUT) A
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_hdll__clkbuf_1 sky130_fd_sc_hdll__clkbuf_2 sky130_fd_sc_hdll__clkbuf_4 sky130_fd_sc_hdll__clkbuf_8"
-set ::env(CTS_MAX_CAP) 1.53169
 set ::env(FP_PDN_RAIL_WIDTH) 0.48
+# Determined from https://github.com/google/skywater-pdk-libs-sky130_fd_sc_hdll/blob/0694bd23893de20f5233ef024acf6cca1e750ac6/cells/clkbuf/sky130_fd_sc_hdll__clkbuf_16__tt_025C_1v80.lib.json
+set ::env(CTS_MAX_CAP) 1.03547
+set ::env(DEFAULT_MAX_TRAN) 0.75
diff --git a/sky130/openlane/sky130_fd_sc_hs/config.tcl b/sky130/openlane/sky130_fd_sc_hs/config.tcl
index 33bcfed..9567587 100755
--- a/sky130/openlane/sky130_fd_sc_hs/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_hs/config.tcl
@@ -63,4 +63,5 @@
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_hs__clkbuf_2 sky130_fd_sc_hs__clkbuf_4 sky130_fd_sc_hs__clkbuf_8"
 set ::env(CTS_MAX_CAP) 1.8894300000
+set ::env(DEFAULT_MAX_TRAN) 0.75
 set ::env(FP_PDN_RAIL_WIDTH) 0.48
diff --git a/sky130/openlane/sky130_fd_sc_hvl/config.tcl b/sky130/openlane/sky130_fd_sc_hvl/config.tcl
index bb2bc50..22fa3a6 100644
--- a/sky130/openlane/sky130_fd_sc_hvl/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_hvl/config.tcl
@@ -71,4 +71,5 @@
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_hvl__buf_1 sky130_fd_sc_hvl__buf_2 sky130_fd_sc_hvl__buf_4 sky130_fd_sc_hvl__buf_8"
 set ::env(CTS_MAX_CAP) 5.57100
+set ::env(DEFAULT_MAX_TRAN) 0.75
 set ::env(FP_PDN_RAIL_WIDTH) 0.51
diff --git a/sky130/openlane/sky130_fd_sc_ls/config.tcl b/sky130/openlane/sky130_fd_sc_ls/config.tcl
index f9c2b90..e77d34e 100755
--- a/sky130/openlane/sky130_fd_sc_ls/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_ls/config.tcl
@@ -66,4 +66,5 @@
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_ls__clkbuf_1 sky130_fd_sc_ls__clkbuf_2 sky130_fd_sc_ls__clkbuf_4 sky130_fd_sc_ls__clkbuf_8"
 set ::env(CTS_MAX_CAP) 1.53169
+set ::env(DEFAULT_MAX_TRAN) 0.75
 set ::env(FP_PDN_RAIL_WIDTH) 0.48
diff --git a/sky130/openlane/sky130_fd_sc_ms/config.tcl b/sky130/openlane/sky130_fd_sc_ms/config.tcl
index 29f2f6d..dc3ca5b 100755
--- a/sky130/openlane/sky130_fd_sc_ms/config.tcl
+++ b/sky130/openlane/sky130_fd_sc_ms/config.tcl
@@ -65,4 +65,5 @@
 set ::env(CLK_BUFFER_OUTPUT) X
 set ::env(CTS_CLK_BUFFER_LIST) "sky130_fd_sc_ms__clkbuf_2 sky130_fd_sc_ms__clkbuf_4 sky130_fd_sc_ms__clkbuf_8"
 set ::env(CTS_MAX_CAP) 1.53169
+set ::env(DEFAULT_MAX_TRAN) 0.75
 set ::env(FP_PDN_RAIL_WIDTH) 0.48