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BMW E24 early six

Early six under test, note single door mirror.

BMW E24 Six Series - Versions Available


Early E24s

630CS / 630CSi

The first E24 model was the now rare 1976 630CS, the only non-injected six, which used basically the same engine as the E9 3.0CS. it was never sold in the UK. The 630CSi followed for US customers in order to meet tougher emissions standards. The earliest examples were built by Karmann on behalf of BMW, they rusted even better than the later cars.

The 3.0CS had used twin Zenith carbs but the 630CS used a sinlge Solex 4A1. This was judged more suitable and was a good unit, but it was difficult to set up well and BMW's engineers were glad to see the back of it.

These cars were around 160kg heavier than the preceding 3.0CSi and had similar power. Their performance was predictably poorer, not a good start for the bigger new coupe. In the US engine power had actually dropped 25bhp to 176 in an effort to meet strict emissions regulations, US sixes would always be down in power for this reason. Early US 630CSi's used the Jetronic-D engine from the US E3 3.0Si saloon.

Manuals were four speed as standard with a 1:1 top ratio, automatics three speed ZF. Both cars had 3.45:1 final drives. The cars had 14" alloys and vented disc brakes all round. In Germany even the passenger wing mirror was an optional extra!

The US 630CSi had a base price of $24,000 and a curb weight of 3470lb (1577kg). It's 8.1:1 compression was a good deal lower than the euro cars and accounted for much of the power loss. It was judged by many reviewers as a good car but not at the price asked.

But it wasn't all bad news compared to the older car as the new Six was much stronger and it's body flexed much less under cornering. Crash protection was significantly better and the car also handled well. There was clearly room for growth.

A euro 625CS had been planned but never saw production.

BMW E24 633CSi

633CSi with 14" Alpina style wheels.


The 200bhp Jetronic-L 633CSi (actually a 3.2) was launched in Europe at the same time as the 630CS in 1976. In the UK it became available in September and cost £12,000 which included electric windows, limited slip differential and air conditioning (expensive options in Germany). Gearboxes were initially the same as the 630CS.

Early reviews praised the worm and sector steering for it's good weighting and precision. The extra interior space, quietness and luxury compared to the older coupe were also well received. Suspension was felt to be good for the long distance touring the car was designed for but a bit soft for truly spirited driving. The car's main downside in the UK was it's high price compared to rivals such as the Jaguar XJS.

A launch model euro 633CSi four speed manual (200bhp) was timed at 7.2s 0-60, that's not far behind what my 1985 635CSi manual could do. I reckoned on 6.7s but was fairly gentle with the clutch as it was my own car. The three speed auto was a more sedate 9.4s.

Early US examples used the terrible thermal reactors from the E12 530i, these killed power and hurt economy badly. Around 1980 these were replaced by a three way catalytic converter which improved things massively.

Around early 1982 (before the facelift) the 633 got a five speed manual transmission as standard. They also went from the analogue clock to a digital one.


The 628CSi was first sold in the UK during the closing months of 1980. BMW UK had dropped the 633CSi a year earlier so a cheaper alternative to the 635CSi was overdue. The new car cost £16,635, someone had a sense of humour! It was almost exactly the same price as a Porsche 911SC but cheaper than an XJS by 2,500 and a 280SL by 1,000. As was typical of 80's BMWs almost anything was an extra. The base price excluded aircon, an automatic gearbox, cruise control, sunroof LSD and even the radio! Once these were added the price rose by a few thousand.

The 2.8 M30 was Jetronic-L (even after the facelift it didn't get Motronic) and was easier to get as a manual than a 635. Compared to it's rivals the 628 and the 635 had excellent fuel economy thanks to their more advanced fuel injection. Visually the 628 lacked the deep front air dam of it's bigger engined brother and had to make do without the boot spoiler. Automatic 628CSi's used the four speed ZF 4HP22 but never had the electronic EH version even as an option as this needed Motronic to control it.

BMW E24 635CSi

1981 635CSi with early style spoiler and short bumper.


In July 1978 things changed for the better, the first version of the legendary 635CSi saw the light of day. Power was now 218bhp from the Jetronic-L fueled engine and the rise in capacity gave a useful torque bonus. This was the car the market demanded and it had taken only two years to emerge. When compared with other 3.5s such as the Rover V8 the BMW unit was in a different league, it made more power drank less fuel and was more reliable. In the UK it was initially sold alongside the cheaper 633CSi rather than as a replacement, in europe the 630CS was still the base model.

The 635 wore the deep front air dam we now associate with the car and (except in the USA) had a standard boot spoiler to complete the sportier look. 14" Mahle cross spoke alloys were fitted, sometimes with a gold centre. Tyres were Michelin 195/70/14s, amazingly narrow to today's eyes.

The four speed gearbox was replaced with a five speed Getrag and the ZF automatic gained a fourth overdrive gear, it wasn't yet the electronic version - that came in 1983. The car now drove with more focus and the five speed gearbox made the power more accessible whilst also improving economy on longer drives.

It's base launch price of £16,499 made the UK 635 an expensive car, it cost 1250 more than an XJS V12. Although as with the 633CSi the UK car had more standard equipment than the German version. It was still around 1,750 less than a Mercedes 450SLC and a mighty 4,000 less than the recently launched Porsche 928.

In late 1980 the 635CSi went to Motronic fuel injection, this was before the facelift which many people find surprising. Motronic was micro-processor controlled, peak power remained the same but economy (already good for such a big car) was further improved. Motronic cars used a totally different intake manifold and are easy to spot.

BMW E24 635CSi 1983

1983 UK 635CSi showing revised bumper.

The 1982 Facelift

The mid-82 facelift took the 635CSi and 628CSi to the place where most enthusiasts know them today. The most prominent outward change was to the rear bumper which became a more elegant wrap around design. But underneath the car had shed 60kg and moved to use the same rear subframe and other suspension components as the E28 five series. This included the brakes, ABS and steering. The suspension changes made the car much more sure footed, especially in the wet.

The main interior changes were to the centre console and dashboard. The speedo was now electronically driven via a Hall Effect sensor in the differential rather than using a mechanical cable drive from the gearbox. It had a new layout which will be more familiar to drivers of modern BMWs and the check control panel was revised. I've never seen a UK 635 without the onboard computer (OBC) so it was likely standard, but it was optional on the 628 which only had a digital clock unless specified otherwise.

The centre console heating controls were now of the type used in the E30 and E28 and the gear lever surround was slimmed down. The door armrest and interior handle design were changed substantially.

BMW E24 1982 635CSi

1982 635CSi with 14" Mahle alloys.

In late 1983 the ZF 4HP22 EH electronically controlled automatic gearbox became available on the 635CSi. This interfaced with the Motronic DME to control kickdown and other functions. The gearbox had an overdrive top gear (0.81:1) and could lock the torque converter in third and fourth gear to save fuel. Cars with this gearbox are easily spotted due to the S/E/1-2-3 knob. In Sport mode the top overdrive gear is locked out and the revs are held higher when changing up.

BMW E24 635CSi

1983 UK 635CSi with TRX alloys.

The US kept the 633CSi during this period, not until 1984 did a US 635CSi enter showrooms. The new model had a reduced 8:1 compression ratio giving 36bhp less than the euro model but with more weight. ABS was available from 1985.

US models got aircon as standard but not the rear spoiler. They had ungainly Federal bumpers. The L6 was a 1987 US only version similar in concept to the later UK Highline cars. Leather dash, door cards, centre console, etc. These worked well on the later euro cars but in warmer states the sun warped the panels. L6's were heavier than normal cars and didn't have the extra power to cope.

M6 / M635CSi

For the US M6 and the M635CSi see the E24 //M Cars page.

BMW E24 facelist

Facelift car with new bumper, Alpina alloys and shadowline trim.

The 1987 Facelift

In mid-87 the E24 had it's final facelift. The most obvious change was to the front and rear bumpers, these were heavier units and designed with the US cars in mind to meet the 5mph Federal impact standards. On the US cars they looked better than the old Federal bumpers. On the euro cars they added weight and divided opinion on their looks. They did look sporty and fitted the body kit image of the later 80's cars, but they lost the lighter touch of the previous version.

There were no major mechanical changes but lots of detail modifications. One of the best was the move to the larger E34 five series brakes all round. These stopped the car far better than the E28 brakes on the 82-87 cars which were never quite good enough to inspire confidence in really quick driving. The new cars had the "bullseye" ellipsoid headlamps giving a better beam pattern.

The rear panel was modified to accept deeper license plates by lowering the bottom line below the tail lights. On the older cars number plates had to be mounted at an angle to fit in some markets.

There were detail changes in the M30 engine too. The cold start injector and it's thermo-time switch went, replaced by a more advanced Motronic system that altered the duty cycle of the injectors on a cold engine in order to give a richer mixture. The oil filter now went in from the top using a handy quick change canister, much easier than the older engines (this can be retrofitted to older cars).

There were to be no more 628CSi's, things had gone up market. Sadly manual cars would become even rarer, at least in the UK. I've never heard of a dog-leg gearbox in a post-87 car, I suspect only the normal five speed was available. I believe LSDs became standard in the UK.

BMW E24 highline 635CSi

A friend's Highline with 16" black centre Alpinas.

635CSi Highline

In the UK these final sixes were called Highlines, even the M635CSi came in Highline trim. The interior was finished in a different style of leather with slight rouching on the seat panels. I think all of these cars had electrically operated sports seats with a memory function. The dashboard, door skins and centre console were all leather covered. Rear headrests were now standard and looked fantastic as always. The covers on the parcel shelf behind the headrests were modified to accept larger speakers. There were also minor design changes to the side panels in the boot.

All Highlines came with TRX alloys as standard although both 16" and 17" Alpinas were a common dealer supplied option.

There was a UK Highline Motorsport Edition of 181 cars. These were equipped with all the standard features of the Highline plus the shadowline (black) exterior trim and //M logos on the seats. They were available in three colour and trim combinations; Misano red with black Nappa leather, Nogaro silver with black Nappa leather and Macao blue with Lotus white Nappa leather. There were no known mechanical difference on the 635CSi although the M635CSi was rumoured to have half a dozen extra horses under the bonnet.

On the final US cars and the L6 there was a optional rear aircon unit which incorporated a cool box.