Specifications Comparison: 2023 GMC Sierra 2500 vs 2018 GMC Sierra 2500

Legroom

Trim	Eng.	Drive train	1st Row Legroom (in)	2nd Row Legroom (in)
HD Pro Crew Cab 159"	6.6L V8	RWD	44	43
HD Pro Crew Cab 172"	6.6L V8	RWD	44	43
HD Pro Double Cab 149"	6.6L V8	RWD	44	35
HD Pro Double Cab 162"	6.6L V8	RWD	44	35
HD Pro Reg Cab 142"	6.6L V8	RWD	44
HD Pro Crew Cab 159"	6.6L V8	4WD	44	43
HD Pro Crew Cab 172"	6.6L V8	4WD	44	43
HD Pro Double Cab 149"	6.6L V8	4WD	44	35
HD Pro Double Cab 162"	6.6L V8	4WD	44	35
HD Pro Reg Cab 142"	6.6L V8	4WD	44
HD SLE Crew Cab 159"	6.6L V8	RWD	44	43
HD SLE Crew Cab 172"	6.6L V8	RWD	44	43
HD SLE Double Cab 149"	6.6L V8	RWD	44	35
HD SLE Double Cab 162"	6.6L V8	RWD	44	35
HD SLE Reg Cab 142"	6.6L V8	RWD	44
HD SLE Crew Cab 159"	6.6L V8	4WD	44	43
HD SLE Crew Cab 172"	6.6L V8	4WD	44	43
HD SLE Double Cab 149"	6.6L V8	4WD	44	35
HD SLE Double Cab 162"	6.6L V8	4WD	44	35
HD SLE Reg Cab 142"	6.6L V8	4WD	44
HD SLT Crew Cab 159"	6.6L V8	RWD	44	43
HD SLT Crew Cab 172"	6.6L V8	RWD	44	43
HD SLT Double Cab 149"	6.6L V8	RWD	44	35
HD SLT Double Cab 162"	6.6L V8	RWD	44	35
HD SLT Crew Cab 159"	6.6L V8	4WD	44	43
HD SLT Crew Cab 172"	6.6L V8	4WD	44	43
HD SLT Double Cab 149"	6.6L V8	4WD	44	35
HD SLT Double Cab 162"	6.6L V8	4WD	44	35
HD AT4 Crew Cab 159"	6.6L V8	4WD	44	43
HD AT4 Crew Cab 172"	6.6L V8	4WD	44	43
HD Denali Crew Cab 159"	6.6L V8	4WD	44	43
HD Denali Crew Cab 172"	6.6L V8	4WD	44	43

Trim	Eng.	Drive train	1st Row Legroom (in)	2nd Row Legroom (in)
HD 2500 Crew Cab	6.0L V8	RWD	45.3	40.9
HD 2500 Crew Cab	6.0L V8	4WD	45.3	40.9
HD 2500 Crew Cab Denali	6.0L V8	RWD	45.3	40.9
HD 2500 Crew Cab Denali	6.0L V8	4WD	45.3	40.9
HD 2500 Crew Cab SLE	6.0L V8	RWD	45.3	40.9
HD 2500 Crew Cab SLE	6.0L V8	4WD	45.3	40.9
HD 2500 Crew Cab SLT	6.0L V8	RWD	45.3	40.9
HD 2500 Crew Cab SLT	6.0L V8	4WD	45.3	40.9
HD 2500 Extended Cab	6.0L V8	RWD	45.3	34.6
HD 2500 Extended Cab	6.0L V8	4WD	45.3	34.6
HD 2500 Extended Cab SLE	6.0L V8	RWD	45.3	34.6
HD 2500 Extended Cab SLE	6.0L V8	4WD	45.3	34.6
HD 2500 Extended Cab SLT	6.0L V8	RWD	45.3	34.6
HD 2500 Extended Cab SLT	6.0L V8	4WD	45.3	34.6
HD 2500 Regular Cab	6.0L V8	RWD	45.3
HD 2500 Regular Cab	6.0L V8	4WD	45.3
HD 2500 Regular Cab SLE	6.0L V8	RWD	45.3
HD 2500 Regular Cab SLE	6.0L V8	4WD	45.3

Trim	Eng.	Drive train	1st Row Legroom (cm)	2nd Row Legroom (cm)
HD Pro Crew Cab 159"	6.6L V8	RWD	111	109
HD Pro Crew Cab 172"	6.6L V8	RWD	111	109
HD Pro Double Cab 149"	6.6L V8	RWD	111	88
HD Pro Double Cab 162"	6.6L V8	RWD	111	88
HD Pro Reg Cab 142"	6.6L V8	RWD	111
HD Pro Crew Cab 159"	6.6L V8	4WD	111	109
HD Pro Crew Cab 172"	6.6L V8	4WD	111	109
HD Pro Double Cab 149"	6.6L V8	4WD	111	88
HD Pro Double Cab 162"	6.6L V8	4WD	111	88
HD Pro Reg Cab 142"	6.6L V8	4WD	111
HD SLE Crew Cab 159"	6.6L V8	RWD	111	109
HD SLE Crew Cab 172"	6.6L V8	RWD	111	109
HD SLE Double Cab 149"	6.6L V8	RWD	111	88
HD SLE Double Cab 162"	6.6L V8	RWD	111	88
HD SLE Reg Cab 142"	6.6L V8	RWD	111
HD SLE Crew Cab 159"	6.6L V8	4WD	111	109
HD SLE Crew Cab 172"	6.6L V8	4WD	111	109
HD SLE Double Cab 149"	6.6L V8	4WD	111	88
HD SLE Double Cab 162"	6.6L V8	4WD	111	88
HD SLE Reg Cab 142"	6.6L V8	4WD	111
HD SLT Crew Cab 159"	6.6L V8	RWD	111	109
HD SLT Crew Cab 172"	6.6L V8	RWD	111	109
HD SLT Double Cab 149"	6.6L V8	RWD	111	88
HD SLT Double Cab 162"	6.6L V8	RWD	111	88
HD SLT Crew Cab 159"	6.6L V8	4WD	111	109
HD SLT Crew Cab 172"	6.6L V8	4WD	111	109
HD SLT Double Cab 149"	6.6L V8	4WD	111	88
HD SLT Double Cab 162"	6.6L V8	4WD	111	88
HD AT4 Crew Cab 159"	6.6L V8	4WD	111	109
HD AT4 Crew Cab 172"	6.6L V8	4WD	111	109
HD Denali Crew Cab 159"	6.6L V8	4WD	111	109
HD Denali Crew Cab 172"	6.6L V8	4WD	111	109

Trim	Eng.	Drive train	1st Row Legroom (cm)	2nd Row Legroom (cm)
HD 2500 Crew Cab	6.0L V8	RWD	115.1	103.9
HD 2500 Crew Cab	6.0L V8	4WD	115.1	103.9
HD 2500 Crew Cab Denali	6.0L V8	RWD	115.1	103.9
HD 2500 Crew Cab Denali	6.0L V8	4WD	115.1	103.9
HD 2500 Crew Cab SLE	6.0L V8	RWD	115.1	103.9
HD 2500 Crew Cab SLE	6.0L V8	4WD	115.1	103.9
HD 2500 Crew Cab SLT	6.0L V8	RWD	115.1	103.9
HD 2500 Crew Cab SLT	6.0L V8	4WD	115.1	103.9
HD 2500 Extended Cab	6.0L V8	RWD	115.1	87.9
HD 2500 Extended Cab	6.0L V8	4WD	115.1	87.9
HD 2500 Extended Cab SLE	6.0L V8	RWD	115.1	87.9
HD 2500 Extended Cab SLE	6.0L V8	4WD	115.1	87.9
HD 2500 Extended Cab SLT	6.0L V8	RWD	115.1	87.9
HD 2500 Extended Cab SLT	6.0L V8	4WD	115.1	87.9
HD 2500 Regular Cab	6.0L V8	RWD	115.1
HD 2500 Regular Cab	6.0L V8	4WD	115.1
HD 2500 Regular Cab SLE	6.0L V8	RWD	115.1
HD 2500 Regular Cab SLE	6.0L V8	4WD	115.1