Specifications Comparison: 2021 GMC Sierra 2500 vs 2015 GMC Sierra 2500

Legroom

Trim	Eng.	Drive train	1st Row Legroom (in)	2nd Row Legroom (in)
HD Crew Cab	6.6L V8	RWD	44	43
HD Crew Cab	6.6L V8	RWD	44	43
HD Crew Cab	6.6L V8	4WD	44	43
HD Crew Cab	6.6L V8	4WD	44	43
HD Crew Cab AT4	6.6L V8	4WD	44	43
HD Crew Cab AT4	6.6L V8	4WD	44	43
HD Crew Cab Denali	6.6L V8	4WD	44	43
HD Crew Cab Denali	6.6L V8	4WD	44	43
HD Crew Cab SLE	6.6L V8	RWD	44	43
HD Crew Cab SLE	6.6L V8	RWD	44	43
HD Crew Cab SLE	6.6L V8	4WD	44	43
HD Crew Cab SLE	6.6L V8	4WD	44	43
HD Crew Cab SLT	6.6L V8	RWD	44	43
HD Crew Cab SLT	6.6L V8	RWD	44	43
HD Crew Cab SLT	6.6L V8	4WD	44	43
HD Crew Cab SLT	6.6L V8	4WD	44	43
HD Extended Cab	6.6L V8	RWD	44	35
HD Extended Cab	6.6L V8	RWD	44	35
HD Extended Cab	6.6L V8	4WD	44	35
HD Extended Cab	6.6L V8	4WD	44	35
HD Extended Cab SLE	6.6L V8	RWD	44	35
HD Extended Cab SLE	6.6L V8	RWD	44	35
HD Extended Cab SLE	6.6L V8	4WD	44	35
HD Extended Cab SLE	6.6L V8	4WD	44	35
HD Extended Cab SLT	6.6L V8	RWD	44	35
HD Extended Cab SLT	6.6L V8	RWD	44	35
HD Extended Cab SLT	6.6L V8	4WD	44	35
HD Extended Cab SLT	6.6L V8	4WD	44	35
HD Regular Cab	6.6L V8	RWD	44
HD Regular Cab	6.6L V8	RWD	44
HD Regular Cab	6.6L V8	4WD	44
HD Regular Cab	6.6L V8	4WD	44
HD Regular Cab SLE	6.6L V8	RWD	44
HD Regular Cab SLE	6.6L V8	RWD	44
HD Regular Cab SLE	6.6L V8	4WD	44
HD Regular Cab SLE	6.6L V8	4WD	44

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

Trim	Eng.	Drive train	1st Row Legroom (cm)	2nd Row Legroom (cm)
HD Crew Cab	6.6L V8	RWD	111	109
HD Crew Cab	6.6L V8	RWD	111	109
HD Crew Cab	6.6L V8	4WD	111	109
HD Crew Cab	6.6L V8	4WD	111	109
HD Crew Cab AT4	6.6L V8	4WD	111	109
HD Crew Cab AT4	6.6L V8	4WD	111	109
HD Crew Cab Denali	6.6L V8	4WD	111	109
HD Crew Cab Denali	6.6L V8	4WD	111	109
HD Crew Cab SLE	6.6L V8	RWD	111	109
HD Crew Cab SLE	6.6L V8	RWD	111	109
HD Crew Cab SLE	6.6L V8	4WD	111	109
HD Crew Cab SLE	6.6L V8	4WD	111	109
HD Crew Cab SLT	6.6L V8	RWD	111	109
HD Crew Cab SLT	6.6L V8	RWD	111	109
HD Crew Cab SLT	6.6L V8	4WD	111	109
HD Crew Cab SLT	6.6L V8	4WD	111	109
HD Extended Cab	6.6L V8	RWD	111	88
HD Extended Cab	6.6L V8	RWD	111	88
HD Extended Cab	6.6L V8	4WD	111	88
HD Extended Cab	6.6L V8	4WD	111	88
HD Extended Cab SLE	6.6L V8	RWD	111	88
HD Extended Cab SLE	6.6L V8	RWD	111	88
HD Extended Cab SLE	6.6L V8	4WD	111	88
HD Extended Cab SLE	6.6L V8	4WD	111	88
HD Extended Cab SLT	6.6L V8	RWD	111	88
HD Extended Cab SLT	6.6L V8	RWD	111	88
HD Extended Cab SLT	6.6L V8	4WD	111	88
HD Extended Cab SLT	6.6L V8	4WD	111	88
HD Regular Cab	6.6L V8	RWD	111
HD Regular Cab	6.6L V8	RWD	111
HD Regular Cab	6.6L V8	4WD	111
HD Regular Cab	6.6L V8	4WD	111
HD Regular Cab SLE	6.6L V8	RWD	111
HD Regular Cab SLE	6.6L V8	RWD	111
HD Regular Cab SLE	6.6L V8	4WD	111
HD Regular Cab SLE	6.6L V8	4WD	111

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