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ZF 8HP
Automatic Transmission 8HP 70
Overview
Manufacturer	ZF Friedrichshafen
Production	2008–present
Body and chassis
Class	8-speed automatic transmission
Related	GM 8L · Aisin-Toyota 8-speed · MB 9G-Tronic · ZF 9HP
Chronology
Predecessor	ZF 6HP

8HP is ZF Friedrichshafen AG's trademark name for its 8-speed automatic transmission models with hydraulic converter and planetary gearsets for longitudinal engine applications. Designed and first built by ZF's subsidiary in Saarbrücken, Germany, it debuted in 2008 on the BMW 7 Series (F01) 760Li sedan fitted with the V12 engine. BMW remains a major customer for the transmission.

Another major customer is Stellantis, who both received a license to produce the transmission and set up a joint-venture plant with ZF. Stellantis has built the transmission at its Kokomo Transmission plant since 2013 under their own brand name, the Torqueflite 8. The joint venture plant in Gray Court, South Carolina opened in 2012.

The 8HP is the first transmission to use this 8-speed gearset concept. In the meantime it has become the new benchmark for automatic transmissions.

The GM 8L transmission is based on the same globally patented gearset concept. While fully retaining the gearset logic, it differs from this only in the patented arrangement of the components with gearsets 1 and 3 swapped.

Specifications

2008: Pilot Series

The 8HP 70 transmission with the gearset 4 in 23-85-teeth-configuration was the pilot series and therefore without generation designation. It was first used in the BMW 7 Series (F01) 760Li, has a torque handling limit of 700 N⋅m (516 lb⋅ft), and weighs 87 kg (192 lb).

2010: 1st Generation

In addition to the rear-wheel drive variant, two different four-wheel drive versions were available, with a version destined for Volkswagen Group applications using a Torsen centre differential. It is able to encompass a torque range from 300 N⋅m (221 lb⋅ft) to 1,000 N⋅m (738 lb⋅ft), and is available for use in middle-class cars through to large luxury sport utility vehicles.

Since gearset 4 meshes in almost all gears up to and including 5th gear, large gear wheels are advantageous for durability. As the very high ratio 1st gear is formed exclusively by gearset 4, its sun gear is unusually small. For this reason, this gearset was enlarged by over 20 % when the 1st generation was introduced, even if this advantage had to be given up again immediately when the 2nd generation was introduced in order to increase the total span.

2014: 2nd Generation

Efficiency improvements over the pilot design and the first generation include a wider ratio span of 7.81, reduced drag torque from the shift elements, reduction in required oil pump pressure, and broadened use of the coasting and start-stop systems. ZF estimated fuel economy improvement over first generation to be 3 %. Refinements were also made with respect to vibration.

2018: 3rd Generation

Major improvements are total span of 8.59 and a fuel economy improvement of 2.5 % compared to the second generation. There are several options in maximum torque available, also the gearbox is available with mild hybrid and plug in hybrid options: With 15 kW (20 hp) and 200 N⋅m (148 lb⋅ft) supporting boosting and recuperation in combination with 48 Volt technology up to 90 kW (121 hp) and 250 N⋅m (184 lb⋅ft) for usage with higher voltage.

2022: 4th Generation

Major improvement is the transition to a versatile modular system that allows vehicle manufacturers to comprehensively and flexibly electrify their models as required. Plug-in Hybrid options with up to 160 kW (215 hp) and 280 N⋅m (207 lb⋅ft) are capable of saving up to 70 % of carbon emissions compared with a purely conventional variant of the 8HP according to the Worldwide Harmonised Light Vehicles Test Procedure (WLTP). In addition, a modification to gearset 3 increased the reverse gear ratio, making it less disadvantageous. With this gearset concept, the already disadvantageously large step from 7th to 8th gear is further increased, albeit only slightly.

Layout (Gearset Concept) Progress

The main objective in replacing the predecessor model was to improve vehicle fuel economy with extra speeds and a wider gear span to allow the engine speed level to be lowered (downspeeding). Compared to the 6-speed ZF 6HP transmission it uses 12 % less fuel, and 14 % less than a 5-speed transmission. Due to changes in internal design, the shift times have reduced to 0.2 seconds; additionally, the unit brings the ability to shift in a non-sequential manner – going from gear 8 to gear 2 in extreme situations simply by changing one shift element (actuating break B and releasing clutch D).

Progress Quality

In order to increase the number of ratios, ZF has abandoned the conventional design method of limiting themselves to pure in-line epicyclic gearing and extended it to a combination with parallel epicyclic gearing. This was only possible thanks to computer-aided design and has resulted in a globally patented gearset concept. The resulting progress is reflected in a better ratio of the number of gears to the number of components used compared to existing layouts. The 8HP has become the new reference standard (benchmark) for automatic transmissions.

Innovative Strength Analysis

With Asessment	Output: Gear Ratios	Innovation Elasticity Δ Output : Δ Input	Input: Main Components
			Total	Gearsets	Brakes	Clutches
8HP Ref. Object	${\displaystyle n_{O1}}$ ${\displaystyle n_{O2}}$	Topic	${\displaystyle n_{I}=n_{G}+}$ ${\displaystyle n_{B}+n_{C}}$	${\displaystyle n_{G1}}$ ${\displaystyle n_{G2}}$	${\displaystyle n_{B1}}$ ${\displaystyle n_{B2}}$	${\displaystyle n_{C1}}$ ${\displaystyle n_{C2}}$
Δ Number	${\displaystyle n_{O1}-n_{O2}}$		${\displaystyle n_{I1}-n_{I2}}$	${\displaystyle n_{G1}-n_{G2}}$	${\displaystyle n_{B1}-n_{B2}}$	${\displaystyle n_{C1}-n_{C2}}$
Relative Δ	Δ Output ${\displaystyle {\tfrac {n_{O1}-n_{O2}}{n_{O2}}}}$	${\displaystyle {\tfrac {n_{O1}-n_{O2}}{n_{O2}}}:{\tfrac {n_{I1}-n_{I2}}{n_{I2}}}}$ ${\displaystyle ={\tfrac {n_{O1}-n_{O2}}{n_{O2}}}}$·${\displaystyle {\tfrac {n_{I2}}{n_{I1}-n_{I2}}}}$	Δ Input ${\displaystyle {\tfrac {n_{I1}-n_{I2}}{n_{I2}}}}$	${\displaystyle {\tfrac {n_{G1}-n_{G2}}{n_{G2}}}}$	${\displaystyle {\tfrac {n_{B1}-n_{B2}}{n_{B2}}}}$	${\displaystyle {\tfrac {n_{C1}-n_{C2}}{n_{C2}}}}$
8HP 6HP	8 6	Progress	9 8	4 3	2 2	3 3
Δ Number	2		1	1	0	0
Relative Δ	0.333 ${\displaystyle {\tfrac {1}{3}}}$	2.667 ${\displaystyle {\tfrac {1}{3}}:{\tfrac {1}{8}}={\tfrac {1}{3}}}$·${\displaystyle {\tfrac {8}{1}}={\tfrac {8}{3}}}$	0.125 ${\displaystyle {\tfrac {1}{8}}}$	0.333 ${\displaystyle {\tfrac {1}{3}}}$	0.000 ${\displaystyle {\tfrac {0}{2}}}$	0.000 ${\displaystyle {\tfrac {0}{3}}}$
8HP 3-Speed	8 3	Market Position	9 7	4 2	2 3	3 2
Δ Number	5		2	2	-1	1
Relative Δ	1.667 ${\displaystyle {\tfrac {5}{3}}}$	5.833 ${\displaystyle {\tfrac {5}{3}}:{\tfrac {2}{7}}={\tfrac {5}{3}}}$·${\displaystyle {\tfrac {7}{2}}={\tfrac {35}{6}}}$	0.286 ${\displaystyle {\tfrac {2}{7}}}$	1.000 ${\displaystyle {\tfrac {1}{1}}}$	−0.333 ${\displaystyle {\tfrac {-1}{3}}}$	0.500 ${\displaystyle {\tfrac {1}{2}}}$
^ Innovation Elasticity Classifies Progress And Market Position Automobile manufacturers drive forward technical developments primarily in order to remain competitive or to achieve or defend technological leadership. This technical progress has therefore always been subject to economic constraints Only innovations whose relative additional benefit is greater than the relative additional resource input, i.e. whose economic elasticity is greater than 1, are considered for realization The required innovation elasticity of an automobile manufacturer depends on its expected return on investment. The basic assumption that the relative additional benefit must be at least twice as high as the relative additional resource input helps with orientation negative, if the output increases and the input decreases, is perfect 2 or above is good 1 or above is acceptable (red) below this is unsatisfactory (bold) Direct Predecessor To reflect the progress of the specific model change ^ plus 1 reverse gear of which 2 gearsets are combined as a compound Ravigneaux gearset Reference Standard (Benchmark) 3-speed transmissions with torque converters have established the modern market for automatic transmissions and thus made it possible in the first place, as this design proved to be a particularly successful compromise between cost and performance It became the archetype and dominated the world market for around 3 decades, setting the standard for automatic transmissions. It was only when fuel consumption became the focus of interest that this design reached its limits, which is why it has now completely disappeared from the market What has remained is the orientation that it offers as a reference standard (point of reference, benchmark) for this market for determining progressiveness and thus the market position of all other, later designs All transmission variants consist of 7 main components Typical examples are Turbo-Hydramatic from GM Cruise-O-Matic from Ford TorqueFlite from Chrysler Detroit Gear from BorgWarner for Studebaker BW-35 from BorgWarner and as T35 from Aisin 3N 71 from Nissan/Jatco 3 HP from ZF Friedrichshafen W3A 040 and W3B 050 from Mercedes-Benz

Layout Quality

The ratios of the 8 gears are relatively unevenly distributed in all versions. Particularly noticeable are the too small step between 3rd and 4th gear and the too large one between 7th and 8th gear. This cannot be eliminated without affecting all other gear ratios. On the other hand the selected gearset concept offers 2 to 3 gears more than conventional transmissions of comparable manufacturing costs, which more than compensates for the weaknesses.

Gear Ratio Analysis

With Assessment			Planetary Gearset: Teeth				Count	Total Center	Avg.
Model Type	Version		S1 R1	S2 R2	S3 R3	S4 R4	Brakes Clutches	Ratio Span	Gear Step
Gear Ratio	R ${\displaystyle {i_{R}}}$	1 ${\displaystyle {i_{1}}}$	2 ${\displaystyle {i_{2}}}$	3 ${\displaystyle {i_{3}}}$	4 ${\displaystyle {i_{4}}}$	5 ${\displaystyle {i_{5}}}$	6 ${\displaystyle {i_{6}}}$	7 ${\displaystyle {i_{7}}}$	8 ${\displaystyle {i_{8}}}$
Step	${\displaystyle -{\tfrac {i_{R}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{2}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{3}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{4}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{5}}{i_{6}}}}$	${\displaystyle {\tfrac {i_{6}}{i_{7}}}}$	${\displaystyle {\tfrac {i_{7}}{i_{8}}}}$
Δ Step			${\displaystyle {\tfrac {i_{1}}{i_{2}}}:{\tfrac {i_{2}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{2}}{i_{3}}}:{\tfrac {i_{3}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{3}}{i_{4}}}:{\tfrac {i_{4}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{4}}{i_{5}}}:{\tfrac {i_{5}}{i_{6}}}}$	${\displaystyle {\tfrac {i_{5}}{i_{6}}}:{\tfrac {i_{6}}{i_{7}}}}$	${\displaystyle {\tfrac {i_{6}}{i_{7}}}:{\tfrac {i_{7}}{i_{8}}}}$
Shaft Speed	${\displaystyle {\tfrac {i_{1}}{i_{R}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{6}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{7}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{8}}}}$
Δ Shaft Speed	${\displaystyle 0-{\tfrac {i_{1}}{i_{R}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{1}}}-0}$	${\displaystyle {\tfrac {i_{1}}{i_{2}}}-{\tfrac {i_{1}}{i_{1}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{3}}}-{\tfrac {i_{1}}{i_{2}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{4}}}-{\tfrac {i_{1}}{i_{3}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{5}}}-{\tfrac {i_{1}}{i_{4}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{6}}}-{\tfrac {i_{1}}{i_{5}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{7}}}-{\tfrac {i_{1}}{i_{6}}}}$	${\displaystyle {\tfrac {i_{1}}{i_{8}}}-{\tfrac {i_{1}}{i_{7}}}}$
2008: Pilot Series
8HP 70	700 N⋅m (516 lb⋅ft)		48 96	48 96	69 111	23 85	2 3	7.0435 1.7693	1.3216
Gear Ratio	−3.2968 ${\displaystyle -{\tfrac {1,744}{529}}}$	4.6957 ${\displaystyle {\tfrac {108}{23}}}$	3.1304 ${\displaystyle {\tfrac {72}{23}}}$	2.1039 ${\displaystyle {\tfrac {162}{77}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2845 ${\displaystyle {\tfrac {8,826}{6,871}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8392 ${\displaystyle {\tfrac {120}{143}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.7021	1.0000	1.5000	1.4879	1.2623	1.2975	1.2845	1.1917	1.2587
Δ Step			1.0081	1.1787	0.9729	1.0101	1.0779	0.9467
Speed	-1.4243	1.0000	1.5000	2.2319	2.8174	3.6555	4.6957	5.5957	7.0435
Δ Speed	1.4243	1.0000	0.5000	0.7319	0.5855	0.8382	1.0401	0.9000	1.4478
2010: 1st Generation
8HP 30/I 8HP 45	300 N⋅m (221 lb⋅ft) 450 N⋅m (332 lb⋅ft)		48 96	48 96	60 96	28 104	2 3	7.0714 1.7728	1.3224
Gear Ratio	−3.2952 ${\displaystyle -{\tfrac {346}{105}}}$	4.7143 ${\displaystyle {\tfrac {33}{7}}}$	3.1429 ${\displaystyle {\tfrac {22}{7}}}$	2.1064 ${\displaystyle {\tfrac {99}{47}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2854 ${\displaystyle {\tfrac {1,171}{911}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8387 ${\displaystyle {\tfrac {26}{31}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.6990	1.0000	1.5000	1.4921	1.2638	1.2966	1.2854	1.1923	1.2581
Δ Step			1.0053	1.1805	0.9747	1.0087	1.0781	0.9477
Speed	-1.4306	1.0000	1.5000	2.2381	2.8286	3.6576	4.7143	5.6209	7.0714
Δ Speed	1.4306	1.0000	0.5000	0.7381	0.5905	0.8390	1.0467	0.9066	1.45058
8HP 55 8HP 65 8HP 70 8HP 90	650 N⋅m (479 lb⋅ft) 650 N⋅m (479 lb⋅ft) 700 N⋅m (516 lb⋅ft) 900 N⋅m (664 lb⋅ft)		48 96	48 96	69 111	28 104	2 3	7.0714 1.7728	1.3224
Gear Ratio	−3.3168 ${\displaystyle -{\tfrac {534}{161}}}$	4.7143 ${\displaystyle {\tfrac {33}{7}}}$	3.1429 ${\displaystyle {\tfrac {22}{7}}}$	2.1064 ${\displaystyle {\tfrac {99}{47}}}$	1.6667 ${\displaystyle {\tfrac {5}{3}}}$	1.2847 ${\displaystyle {\tfrac {5,397}{4,201}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8392 ${\displaystyle {\tfrac {120}{143}}}$	0.6667 ${\displaystyle {\tfrac {2}{3}}}$
Step	0.7036	1.0000	1.5000	1.4921	1.2638	1.2973	1.2847	1.1917	1.2587
Δ Step			1.0053	1.1806	0.9742	1.0098	1.0781	0.9467
Speed	-1.4213	1.0000	1.5000	2.2381	2.8286	3.6696	4.7143	5.6179	7.0714
Δ Speed	1.4243	1.0000	0.5000	0.7381	0.5905	0.8410	1.0447	0.9036	1.4536
2014: 2nd Generation
8HP 75/I	740 N⋅m (546 lb⋅ft)		48 96	48 96	69 111	28 104	2 3	7.0714 1.7728	1.3224
Ratio	−3.3168	4.7143	3.1429	2.1064	1.6667	1.2847	1.0000	0.8392	0.6667
8HP 30/II 8HP 50	300 N⋅m (221 lb⋅ft) 500 N⋅m (369 lb⋅ft)		48 96	54 96	60 96	24 96	2 3	7.8125 1.7889	1.3413
Gear Ratio	−3.4560 ${\displaystyle -{\tfrac {432}{125}}}$	5.0000 ${\displaystyle {\tfrac {5}{1}}}$	3.2000 ${\displaystyle {\tfrac {16}{5}}}$	2.1429 ${\displaystyle {\tfrac {15}{7}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3139 ${\displaystyle {\tfrac {1,507}{1,147}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8221 ${\displaystyle {\tfrac {208}{253}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.6912	1.0000	1.5625	1.4933	1.2458	1.3091	1.3139	1.2163	1.2846
Δ Step			1.0463	1.1986	0.9517	0.9964	1.0802	0.9469
Speed	-1.4468	1.0000	1.5625	2.3333	2.9070	3.8056	5.0000	6.0817	7.8125
Δ Speed	1.4468	1.0000	0.5625	0.7708	0.5736	0.8986	1.1944	1.0817	1.7308
8HP 75/II 8HP 95	740 N⋅m (546 lb⋅ft) 900 N⋅m (664 lb⋅ft)		48 96	54 96	69 111	24 96	2 3	7.8125 1.7889	1.3413
Gear Ratio	−3.4783 ${\displaystyle -{\tfrac {80}{23}}}$	5.0000 ${\displaystyle {\tfrac {5}{1}}}$	3.2000 ${\displaystyle {\tfrac {16}{5}}}$	2.1429 ${\displaystyle {\tfrac {15}{7}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3131 ${\displaystyle {\tfrac {2,315}{1,763}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8226 ${\displaystyle {\tfrac {320}{389}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.6957	1.0000	1.5625	1.4933	1.2458	1.3099	1.3131	1.2156	1.2853
Δ Step			1.0463	1.1986	0.9511	0.9975	1.0802	0.9458
Speed	-1.4375	1.0000	1.5625	2.3333	2.9070	3.8078	5.0000	6.0781	7.8125
Δ Speed	1.4375	1.0000	0.5625	0.7708	0.5736	0.9008	1.1922	1.0781	1.7344
2018: 3rd Generation
8HP 76/I	760 N⋅m (561 lb⋅ft)		48 96	54 96	69 111	24 96	2 3	7.8125 1.7889	1.3413
Ratio	−3.4783	5.0000	3.2000	2.1429	1.7200	1.3131	1.0000	0.8226	0.6400
8HP 30/III 8HP 51	300 N⋅m (221 lb⋅ft) 500 N⋅m (369 lb⋅ft)		48 96	54 96	60 96	24 102	2 3	8.2031 1.8330	1.3507
Gear Ratio	−3.7120 ${\displaystyle -{\tfrac {464}{125}}}$	5.2500 ${\displaystyle {\tfrac {21}{4}}}$	3.3600 ${\displaystyle {\tfrac {84}{25}}}$	2.1724 ${\displaystyle {\tfrac {63}{29}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3161 ${\displaystyle {\tfrac {6,371}{4,841}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8221 ${\displaystyle {\tfrac {208}{253}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.7070	1.0000	1.5625	1.5467	1.2630	1.3069	1.3161	1.2163	1.2846
Δ Step			1.0102	1.2246	0.9664	0.9931	1.0820	0.9469
Speed	-1.4143	1.0000	1.5625	2.4167	3.0523	3.9892	5.2500	6.3858	8.2031
Δ Speed	1.4143	1.0000	0.5625	0.8542	0.6357	0.9369	1.2608	1.1358	1.8173
8HP 76/II	760 N⋅m (561 lb⋅ft)		48 96	54 96	69 111	24 108	2 3	8.5938 1.8762	1.3597
Gear Ratio	−3.9930 ${\displaystyle -{\tfrac {2,296}{575}}}$	5.5000 ${\displaystyle {\tfrac {11}{2}}}$	3.5200 ${\displaystyle {\tfrac {88}{25}}}$	2.2000 ${\displaystyle {\tfrac {11}{5}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3172 ${\displaystyle {\tfrac {191}{145}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8226 ${\displaystyle {\tfrac {320}{389}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.7260	1.0000	1.5625	1.6000	1.2791	1.3058	1.3172	1.2156	1.2853
Δ Step			0.9766	1.2509	0.9796	0.9913	1.0836	0.9458
Speed	-1.3774	1.0000	1.5625	2.5000	3.1977	4.1754	5.5000	6.6859	8.5938
Δ Speed	1.3774	1.0000	0.5625	0.9375	0.6977	0.9777	1.3246	1.1859	1.8321
2022: 4th Generation
8HP 100	1,000 N⋅m (738 lb⋅ft)		48 96	54 96	60 108	24 96	2 3	7.8125 1.7889	1.3413
Gear Ratio	−3.9680 ${\displaystyle -{\tfrac {496}{125}}}$	5.0000 ${\displaystyle {\tfrac {5}{1}}}$	3.2000 ${\displaystyle {\tfrac {16}{5}}}$	2.1429 ${\displaystyle {\tfrac {15}{7}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.2973 ${\displaystyle {\tfrac {1,571}{1,211}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8327 ${\displaystyle {\tfrac {224}{269}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.7936	1.0000	1.5625	1.4933	1.2458	1.3259	1.2973	1.2009	1.3011
Δ Step			1.0463	1.1986	0.9397	1.0220	1.0803	0.9230
Speed	-1.2601	1.0000	1.5625	2.3333	2.9070	3.8542	5.0000	6.0045	7.8125
Δ Speed	1.2601	1.0000	0.5625	0.7708	0.5736	0.9473	1.1458	1.0045	1.8080
8HP 80	800 N⋅m (590 lb⋅ft)		48 96	54 96	60 108	24 108	2 3	8.5938 1.8762	1.3597
Gear Ratio	−4.5440 ${\displaystyle -{\tfrac {1,704}{375}}}$	5.5000 ${\displaystyle {\tfrac {11}{2}}}$	3.5200 ${\displaystyle {\tfrac {88}{25}}}$	2.2000 ${\displaystyle {\tfrac {11}{5}}}$	1.7200 ${\displaystyle {\tfrac {43}{25}}}$	1.3010 ${\displaystyle {\tfrac {389}{299}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8327 ${\displaystyle {\tfrac {224}{269}}}$	0.6400 ${\displaystyle {\tfrac {16}{25}}}$
Step	0.8262	1.0000	1.5625	1.6000	1.2791	1.3221	1.3010	1.2009	1.3011
Δ Step			0.9766	1.2509	0.9675	1.0162	1.0834	0.9230
Speed	-1.2104	1.0000	1.5625	2.5000	3.1977	4.2275	5.5000	6.6049	8.5938
Δ Speed	1.2104	1.0000	0.5625	0.9375	0.6977	1.0298	1.2725	1.1049	1.9888
2016: Racing Cars
8P 45R	450 N⋅m (332 lb⋅ft) up to 1,050 N⋅m (774 lb⋅ft)		TBD	TBD	60 96	TBD	2 3	4.2000 TBD	1.2275
Ratio	TBD	TBD	TBD	TBD	TBD	TBD	1.0000	TBD	TBD
2017: Commercial Vehicles
8AP 600 T 8AP 800 T 8AP 1000 T 8AP 1200 T	600 N⋅m (443 lb⋅ft) 800 N⋅m (590 lb⋅ft) 1,000 N⋅m (738 lb⋅ft) 1,200 N⋅m (885 lb⋅ft)		65 115	65 115	62 122	27 105	2 3	7.6522 1.7673	1.3374
Gear Ratio	−4.2501 ${\displaystyle -{\tfrac {10,672}{2,511}}}$	4.8889 ${\displaystyle {\tfrac {44}{9}}}$	3.1235 ${\displaystyle {\tfrac {253}{81}}}$	2.0334 ${\displaystyle {\tfrac {1,584}{779}}}$	1.6389 ${\displaystyle {\tfrac {59}{36}}}$	1.2541 ${\displaystyle {\tfrac {123,164}{98,209}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8400 ${\displaystyle {\tfrac {2,116}{2,519}}}$	0.6389 ${\displaystyle {\tfrac {23}{36}}}$
Step	0.8693	1.0000	1.5652	1.5361	1.2407	1.3068	1.2541	1.1905	1.3148
Δ Step			1.0190	1.2381	0.9494	1.0420	1.0535	0.9054
Speed	-1.1503	1.0000	1.5652	2.4043	2.9831	3.8983	4.8889	5.8200	7.6522
Δ Speed	1.1503	1.0000	0.5652	0.8391	0.5787	0.9153	0.9906	0.9311	1.8322
8AP 1200 S	1,200 N⋅m (885 lb⋅ft)		65 115	65 115	65 115	27 105	2 3	7.6522 1.7673	1.3374
Gear Ratio	−3.7569 ${\displaystyle -{\tfrac {3,956}{1,053}}}$	4.8889 ${\displaystyle {\tfrac {44}{9}}}$	3.1235 ${\displaystyle {\tfrac {253}{81}}}$	2.0334 ${\displaystyle {\tfrac {1,584}{779}}}$	1.6389 ${\displaystyle {\tfrac {59}{36}}}$	1.2676 ${\displaystyle {\tfrac {49,572}{39,107}}}$	1.0000 ${\displaystyle {\tfrac {1}{1}}}$	0.8305 ${\displaystyle {\tfrac {828}{997}}}$	0.6389 ${\displaystyle {\tfrac {23}{36}}}$
Step	0.7685	1.0000	1.5652	1.5361	1.2407	1.2929	1.2676	1.2041	1.2999
Δ Step			1.0190	1.2381	0.9596	1.0200	1.0527	0.9263
Speed	-1.3013	1.0000	1.5652	2.4043	2.9831	3.8568	4.8889	5.8867	7.6522
Δ Speed	1.3013	1.0000	0.5652	0.8391	0.5787	0.8738	1.0321	0.9979	1.7654
Ratio R & Even	${\displaystyle i_{R}={\tfrac {R_{2}(S_{3}S_{4}-R_{3}R_{4})}{S_{3}S_{4}(S_{2}+R_{2})}}}$		${\displaystyle i_{2}={\tfrac {R_{2}(S_{4}+R_{4})}{(S_{2}+R_{2})S_{4}}}}$		${\displaystyle i_{4}=1+{\tfrac {S_{2}R_{1}}{S_{1}(S_{2}+R_{2})}}}$		${\displaystyle i_{6}={\tfrac {1}{1}}}$	${\displaystyle i_{8}={\tfrac {R_{2}}{S_{2}+R_{2}}}}$
Ratio Odd	${\displaystyle i_{1}={\tfrac {S_{4}+R_{4}}{S_{4}}}}$		${\displaystyle {\tfrac {(S_{1}+R_{1})(S_{4}+R_{4})}{S_{4}R_{1}+S_{1}(S_{4}+R_{4})}}}$		${\displaystyle {\tfrac {S_{1}R_{2}R_{4}(S_{3}+R_{3})+S_{2}S_{3}(S_{1}+R_{1})(S_{4}+R_{4})}{S_{1}R_{4}(S_{3}(S_{2}+R_{2})+R_{2}R_{3})+S_{2}S_{3}S_{4}(S_{1}+R_{1})}}}$			${\displaystyle {\tfrac {R_{2}(S_{3}+R_{3})}{R_{2}(S_{3}+R_{3})+S_{2}S_{3}}}}$
Algebra And Actuated Shift Elements
Brake A	❶	❶	❶					❶	❶
Brake B	❶	❶	❶	❶	❶	❶
Clutch C		❶		❶		❶	❶	❶
Clutch D	❶				❶	❶	❶	❶	❶
Clutch E			❶	❶	❶		❶		❶
Layout Input and output are on opposite sides Planetary gearset 1 is on the input (turbine) side Input shafts are C2 and, if actuated, R3 and S4 Output shaft is C4 (planetary gear carrier of gearset 4) Total Ratio Span (Total Ratio Spread · Total Gear Ratio) ${\displaystyle {\tfrac {i_{n}}{i_{1}}}}$ A wider span enables the downspeeding when driving outside the city limits increase the climbing ability when driving over mountain passes or off-road or when towing a trailer Ratio Span's Center ${\displaystyle (i_{n}i_{1})^{\tfrac {1}{2}}}$ The center indicates the speed level of the transmission Together with the final drive ratio it gives the shaft speed level of the vehicle Average Gear Step ${\displaystyle ({\tfrac {i_{n}}{i_{1}}})^{\tfrac {1}{n-1}}}$ With decreasing step width the gears connect better to each other shifting comfort increases Sun 1: sun gear of gearset 1 Ring 1: ring gear of gearset 1 Sun 2: sun gear of gearset 2 Ring 2: ring gear of gearset 2 Sun 3: sun gear of gearset 3 Ring 3: ring gear of gearset 3 Sun 4: sun gear of gearset 4 Ring 4: ring gear of gearset 4 ^ Standard 50:50 — 50 % Is Above And 50 % Is Below The Average Gear Step — With steadily decreasing gear steps (yellow highlighted line Step) and a particularly large step from 1st to 2nd gear the lower half of the gear steps (between the small gears; rounded down, here the first 3) is always larger and the upper half of the gear steps (between the large gears; rounded up, here the last 4) is always smaller than the average gear step (cell highlighted yellow two rows above on the far right) lower half: smaller gear steps are a waste of possible ratios (red bold) upper half: larger gear steps are unsatisfactory (red bold) ^ Standard R:1 — Reverse And 1st Gear Have The Same Ratio — The ideal reverse gear has the same transmission ratio as 1st gear no impairment when maneuvering especially when towing a trailer a torque converter can only partially compensate for this deficiency Plus 11.11 % minus 10 % compared to 1st gear is good Plus 25 % minus 20 % is acceptable (red) Above this is unsatisfactory (bold) Standard 1:2 — Gear Step 1st To 2nd Gear As Small As Possible — With continuously decreasing gear steps (yellow marked line Step) the largest gear step is the one from 1st to 2nd gear, which for a good speed connection and a smooth gear shift must be as small as possible A gear ratio of up to 1.6667:1 (5:3) is good Up to 1.7500:1 (7:4) is acceptable (red) Above is unsatisfactory (bold) ^ From large to small gears (from right to left) ^ Standard STEP — From Large To Small Gears: Steady And Progressive Increase In Gear Steps — Gear steps should increase: Δ Step (first green highlighted line Δ Step) is always greater than 1 As progressive as possible: Δ Step is always greater than the previous step Not progressively increasing is acceptable (red) Not increasing is unsatisfactory (bold) ^ Standard SPEED — From Small To Large Gears: Steady Increase In Shaft Speed Difference — Shaft speed differences should increase: Δ Shaft Speed (second line marked in green Δ (Shaft) Speed) is always greater than the previous one 1 difference smaller than the previous one is acceptable (red) 2 consecutive ones are a waste of possible ratios (bold) without generation designation Der neue BMW M760 Li xDrive · BMW Medieninformation Deutschland (The new BMW M760 Li xDrive · BMW Media Information Germany) · 02/2016 · p. 23 · and Der neue BMW M760 Li xDrive · Technische Daten · BMW Medieninformation Oesterreich (The new BMW M760 Li xDrive · Technical Specifications · BMW Media Information Austria) · 01/2017 · p. 2 · 800 N⋅m (590 lb⋅ft) narrow total ratio span · preferebly for petrol engines, sports cars, and high performance engines · Alpina B3 Saloon AWD · Technical Data · 730 N⋅m (538 lb⋅ft) Technical specifications · The new BMW 3 Series Sedan · BMW Media Information · 03/2019 · p. 2: BMW 320i Sedan · 300 N⋅m (221 lb⋅ft) loc. cit. · p. 10: BMW M340i xDrive Sedan · 500 N⋅m (369 lb⋅ft) wide total ratio span · preferebly for Diesel engines, offroad cars, and low performance engines · loc. cit. · p. 18: BMW 330d Sedan · 580 N⋅m (428 lb⋅ft) and Alpina D3 S Saloon AWD · Technical Data · 730 N⋅m (538 lb⋅ft) narrow total ratio span · preferebly for petrol engines, sports cars, and high performance engines · The first-ever BMW XM · Market launch September 2022 The all-new BMW M5 · Market launch June 2024 wide total ratio span · preferebly for Diesel engines, offroad cars, and low performance engines · Progress and efficiency with added variety: additional drive system variants and innovations for the new BMW 7 Series · Market launch 2022/2023 Alpina XB7 AWD · Technical Data w/o hydraulic torque converter · narrow total ratio span of 4.2 based on the same gearset concept as the 8HP transmissions Automatic Powershift Transmission for Trucks ^ higher torque on demand ^ 65/115 or 52/92 Automatic Powershift Transmission for Special vehicles Permanently coupled elements S1 and S2 C1 (carrier 1) and R4 R2 and S3 R3 and S4 Blocks S1 and S2 Blocks R1 Couples R3 and S4 with the turbine Couples C3 (carrier 1) with C4 (carrier 4) Couples R2 and S3 with R3 and S4

Applications

1. without any claim of completeness

See also

• List of Chrysler transmissions
• List of ZF transmissions

References

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33. ^ Efficient Torque Converter Automatic Transmission for Commercial Vehicles (ZF 8AP) · Winfried Gründler · Herbert Mozer · Frank Sauter: ATZ worldwide 06/2017 · pp. 36–39
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48. "RR ghost specification". Retrieved 21 February 2010.
49. "New Generation of the 8HP in the BMW 5 Series". Retrieved 20 August 2014.
50. ^ 8HP 75 Data Sheet · p. 4 · Saarbruecken 2016
51. "2016 BMW 7 Series Sedan: Teutonic Technology". 24 September 2015. Retrieved 24 April 2016.
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54. "New vehicles with ZF technology (Japan)". Retrieved 18 June 2011.
55. "BMW Alpina B7 Long-wheelbase AWD Technical Data". Retrieved 10 May 2019.

External links

• Official website

• ZF Friedrichshafen transmissions
• Automatic transmission tradenames
• Chrysler transmissions
• Chrysler
• Auto parts