What was the zero to sixty time for a 1969 Plymouth Hemi Road Runner with 4.10 gears
Executive summary
Published, period testing for the 1969 Plymouth Road Runner equipped with the 426 HEMI and 4.10 rear gears did not consistently publish a canonical 0–60 time, but contemporary quarter‑mile test results and later reference compilations allow a reasoned estimate: period magazine runs with the HEMI and 4.10 gears produced mid‑13‑second quarter‑mile passes at roughly 105 mph, which corresponds to an approximate 0–60 time in the mid‑5 to low‑6 second range when accounting for transmission and testing variables [1] [2] [3].
1. The hard evidence: period quarter‑mile runs, gearing called out
Muscle‑era road tests provide the clearest hard numbers for the HEMI Road Runner with 4.10s: Motor Trend’s February 1969 test (reported in DodgeGarage’s heritage writeup) recorded a best run of 13.56 seconds at 105.38 mph with a car explicitly fitted with 4.10:1 ring‑and‑pinion and a TorqueFlite automatic, and other period magazines produced very similar quarter‑mile times on HEMI Road Runners [1]. Those quarter‑mile benchmarks are the concrete period data points most directly tied to the 4.10‑equipped cars [1].
2. Why quarter‑mile numbers matter for 0–60 estimates
Quarter‑mile trap speeds and ETs are commonly used to back‑calculate 0–60 because most magazines of the era emphasized the quarter‑mile; period tests often omitted a formal 0–60 number while reliably measuring the quarter‑mile. Analysts and later databases use those quarter‑mile figures plus drivetrain and gear ratios to infer 0–60 times; the Road Runner’s ~13.5s @ ~105 mph quarter‑mile is consistent with a 0–60 in the mid‑5 to low‑6 second window under optimal test conditions [1] [2]. Publications that later aggregate performance data note the HEMI’s 425 hp and heavy torque package, plus that the Road Runner’s Dana/60 rear and 4.10 gearing were factory options intended to favor strong launches and straight‑line performance [4] [3].
3. Confounding variables and why sources disagree
Different tests used different transmissions (4‑speed manual vs. Torqueflite auto) and sometimes different rear gears; Car and Driver’s contemporaneous tests used 3.55 ratios in some instances and produced similar quarter‑mile ETs but different launch behavior, while leaving an automatic in Drive rather than using a stall or manual shift could slow ETs by up to about half a second, per period observations [1] [2]. Later forum reports and owner accounts show cars modified with slicks, headers and carburetion tuning running into the low 12s in the quarter with much quicker 0–60s, which underscores how tire, tune and test technique change the number significantly [5] [6].
4. What later compilations list and how to interpret them
Modern compilations and databases vary: some list specific 0–60 times for Road Runner variants (a 1969 Road Runner 440 is listed at 5.5 s in one aggregator, but that is a different engine and should not be conflated with the 426 HEMI) so careful source‑matching is required [7]. Catalog sites that publish full acceleration charts for HEMI models indicate the cars’ raw capability but often derive figures from mixed original test data and simulation, not a single factory 0–60 test [8] [9]. Trusted period quarter‑mile tests remain the best primary evidence for the 4.10 HEMI cars [1].
5. Bottom line — the best supported estimate and caveats
Based on the documented 13.5s @ ~105 mph quarter‑mile runs for HEMI Road Runners equipped with 4.10 gears and period commentary about drivetrain effects, the most defensible, evidence‑anchored estimate for 0–60 mph for a 1969 Plymouth HEMI Road Runner with 4.10 gears is roughly 5.5 to 6.5 seconds under ideal factory test conditions; real‑world examples and tuned cars can be faster or slower depending on transmission choice, tire grip and tuning [1] [2] [3]. The reporting base lacks a single, authoritative published 0–60 for the specific 4.10/HEMI combination, so this range is presented with that limitation in mind [1] [7].