DTW Summer Reissue: Throbby, Thrummy Quints

So who uses five cylinder engines and why? Do they have a future? DTW asks these questions today. Read on to accumulate wisdom on this subject.

1976 Audi 100: five-cylinders available
1976 Audi 100: five-cylinders available.

One might be tempted to think of five cylinder engines as being something of a novelty, if they are not a rarity. However, before Audi and Mercedes in the 1970s, Ford experimented with the concept in the 1930s and 1940s but never put anything into production. The heyday of the five has been from the end of the 70’s until a few years ago. Not a bad run. The window of opportunity for the five-cylinder now seems to be closing. What opened it?

The reasons one might want to use a five-cylinder engine are much the same as for why one might want a four-cylinder instead of a three. You can add capacity and reduce stress. The in-line five cylinder bridges the capacity gap between 2.0 and 2.5 litres. In this capacity a 4-cylinder can be over-stressed and a V6 or in-line six too costly, thirsty and large. A likely starting point is an engine range based on 4-cylinder units that needs expansion to power larger, heavier vehicles than a firm’s four-cylinder range can cope with.

Think of a smallish, middle market firm wanting to punch above its weight. Our list of applications below show this is the case. Firms with sixes seldom tried fives, but firms with fours sometimes did.

In the same way that we have seen that over-stressed small-capacity 4-cylinder engines (as in VW’s 1.4 TSi) can be problematic, a four-cylinder engine seems to be overworked much beyond 2.5 litres. GM’s Iron Duke of the 1970s and 1980s is one example of an overworked four; Lancia tried to offer a large capacity four-cylinder boxer in the 1976 Gamma without success; and in 1978 Saab tried to avoid adding cylinders by turbo-charging the slant 4 Triumph engine. Respectively, these workarounds resulted in coarseness, lack of prestige and unpredictable power delivery. Add to this litany of try-hards the Citroen solution of turbo-charging a 2400 unit to give coarseneness, thirst and turbo-lag in one fine package.

1993 Volvo 850 wagon
1993 Volvo 850 wagon: five doors, five cylinders and five seats.

The quint engine avoids these problems in theory. Furthermore, from the vantage point of considering in-line four cylinders and in-line sixes, an inline five seems like a natural middle point, a transition. In fact, the in-line five might just offer the power of a six but without the torsional rigidity problems of an in-line 6 and bulk of a V6. And a quint can offer the economy of a four but without the need for higher revolutions or too much swept volume.

However, in practice a five-cylinder engine has vertical vibrations that need to be dealt with before accessing the advantages of the torque pulses that come every 144 degrees of crank rotation. Counterweights on the crankshaft (at either end) deal with those vertical motions and tuning of the mounts deal with the other, secondary shakes. The end result is an engine that is shorter than an in-line six, and narrower than a four. It can be mounted transversely too. That’s especially good for front-wheel drive cars (middle market brands, step forward).

1992 Acura Vigor
1992 Acura Vigor: a trendsetter as an early example of the door-shutline and DLO graphics parting company. Lexus pursued this concept.

An early example of the five-cylinder engine is the Mercedes OM617 diesel in 1974. It was economical but deathly slow. Audi claimed a first by installing a quint petrol in a mass produced car in the 1976 Audi 100. Here was an example of a middle-ranking firm trying to build up from a base of fours, as it happens. The 1993 Volvo 850 series was driven by in-line fives of 2.0, 2.3 and 2.4 litres capacity. Sixes didn’t work for them and they needed something better than their tired 2.4 litre four-cylinders used in the 240 series. The 1994 Lancia Kappa went five-ish with 2.0 and 2.5 litre normally-aspirated petrols, along with a turbocharged 2.0. That last one, on paper, seems to offer all the weirdness of a five with the splurgy power-delivery of a turbo. If the 2.4 flat four was like overstretching the four-cylinder concept, a 2.0 turbo charged five seems to cramp the five’s style. The unlamented 1998 Lancia Lybra also came with a five-cylinder engine and this must be the definitive application of the five in a Lancia.

Over in the US of Stateside and Japan, Acura-stroke-Honda offered the Vigor saloon with either a 2.0 or a 2.5 five-cylinder five. Yet again: a brand on the make. Acura is Honda’s upmarket marque so adding swept volume the five-pot way fits in with Honda’s start point of mastery of fours. It wasn’t very popular as people went for either the fours or the sixes and so the 2.5 L G25A and 2.0 L G20A engines were discontinued. VW powered various Boras with 5s (mostly for the US, I gather). Finally, Ford used a five-cylinder in the 2005 Focus ST and in some versions of the S-Max. This promised impressive performance but profligate thirst (the S-Max had two tail-pipes in the hotter versions).

1996 Lancia Kappa 2.0 litre estate
1996 Lancia Kappa 2.0 litre estate: they could have done the rear doors rather better.

Our short catalogue shows a pattern: the five pot engine is ideally suited to front wheel drive, smaller, middle-market marques. The Ford and VW applications are anomalies (and in both cases based on engines developed by other brands).

The future of five looks dim. In 2012 VW and Volvo announced they would discontinue their 5-cylinder engines. The reasons cited involved efficiency (of the engines) and cost (to make). As we have seen in our survey of engines, odd cylinders are in if the count is three. And four cylinder engines are being turbocharged and reduced in volume to satisfy demands for fuel economy. Adding stress, of course, which the five and even larger fours do without.

2005 Ford Focus ST
2005 Ford Focus ST: manic and dipsomaniac.

Here at DTW we tend to favour diversity and the demise of the in-line five simply means a little less colour in the automotive world. I suspect the five-cylinder engine is indeed not a natural format as the four and six are, for reasons of harmonics and symmetry. But the five had what old folks called “character”. I’ve experienced the five cylinder engines in the Lancia Kappa and the Volvo S70 and I quite like the thrum and roar of the units. The engine certainly fitted in with Lancia’s eccentric, Alpine character. And the Volvo’s unit is able to haul their drab slab along uncomplainingly and without stress. A four-pot moving such a car would be working too hard and a V6 would speak against Volvo’s social democratic value. Fives had their uses.

Author: richard herriott

I like anchovies. I dislike post-war town planning.

14 thoughts on “DTW Summer Reissue: Throbby, Thrummy Quints”

  1. The grave thrumming of an idling five cylinder engine is one of the most consoling sounds I know.

    1. My father’s S70 had one. It roars rather and I liked that. Rather too late I am beginning to appreciate the 850 and S70. Shame about the colours.

  2. The Fiat SuperFire modular five cylinder engine fitted to a 156JTD was wonderfully growly and characterful for a diesel engine. One of the drawbacks of a transverely mounted inline five was engine access due to its width. Changing the cambelt was an engine out job until they developed a special tool. It is also worth noting that VW’s five was a V5 – derived from the VR6; perhaps to overcome the aforementioned disadvantage. An engine only possible in the VW of the 90’s when anything (except making a profit) seemed possible.

    1. Isn’t the Lancia five-cylinder related to Fiat’s?
      Laurent the Eagle mentioned elsewhere that the Bora/Vento/Jetta (delete as appropriate) had a five-banger as its signature unit. What with its decidedly lux CLX trim, the VentoJettaBora has often trespassed on the Passat which for many years never, ever seemed more than minimally cosy.

    2. That VW VR5 was marvellously wacky, like the sort of configuration which would be tried on a racing motorcycle than a mainstream car. There were rumours that it was devised for a high performance Polo 6N2 which never materialised. A collector of VAG oddities in my neighbourhood has a lovely but fading late ’90s Seat Toledo VR5: gold, beige cow trim, and automatic, which all complement the nicest version of the Golf Mk 4 (in my contrarian opinion).

      Moving on, nobody seems to have a good word for the in-line five used in the US market Golf Mk.5 / Jetta / New Beetle. It was the entry level engine, with a turbo four the next level up. What were they thinking?

  3. The sound of the naturally aspirated Volvo 5-cylinder was unfortunately toned down a bit for the s/v70. In the 850 (especially the 170bhp version) it sounded a bit more grunty, a sounds I have always liked. Have unfortunately not owned one myself though.

    (b.t.w. the 850 wagon in the picture seems to be a 1994 or later judging by the bumpers)

    1. Hi Magnus: if the five sounded roarier in the 850 than the S70 then it must have been quite an assertive sound. The engine noise, comfy seats and vast boot are the bits of the S70 that stand out the most. It was a weighty old car though; the engine roared when encouraged to haul the vehicle’s mass to a useful speed.
      The photo: I can’t recall where I got the image, having added it before our credits policy went into operation. Nice car though. I saw one with a warm interior colour last year. Very much more appealing than the usual sad grey velour.

  4. Richard, as with all engines fitted to Lancias in the past few decades, the five cylinder units are Fiat engines, also used I believe, in the original Bravo, Marea, Coupe, Alfa 159, Brera and 166.

  5. Robertas: the Toledo VR5 is a real Q-car. I imagine your neighbour’s spec is very, very rare.
    And yes, the Jetta in the US is seen as some manner of crap car for graduates. I wonder if the Mexican build has something to do with it. I doubt the Euro version is the same as the N American one in lots of ways.
    Boring it might be but they have sold a lot of them!

  6. Two absentees from the roll of honour:

    The GM Atlas / Vortec 3500 / 3700. Probably the biggest petrol five, almost certainly not the best. Used in various GMC, Chevrolet and “Isuzu” utilities, as well as the oaf’s favourite Hummer H3.

    Land Rover TD5: A direct injection diesel, and by marriage, BMW’s only five. By most accounts pretty good. Someone in the know told me that it was far less closely related to the Rover L series than might be expected. The L series was the final (pre-Sonalika) variant of the BL/ARG/Rover O/M/T series, which shared tooling with the 1954 B series. My informant claims that the Freelander 1 diesel TD4 was not an L series, but a reverse-engineered TD5.

    Nobody’s mentioned Rover’s early ’60s experimentation with a 2472cc five cylinder version of the P6’s ohc four. A prototype engine is on show at BMIHT in Gaydon, and as Eric Morecambe would have said, you can see the join. The carburation arrangements put the early PRV V6s to shame.

    More here:

    http://www.roversd1.nl/roverarchives/5cylinder.html

  7. As far as i’ve been able to research, the inline five layout was perfected, and produced first, by ….
    Lancia, of course, for the 1938 3RO heavy truck. The engine itself was a 6.875 lt heron headed, inline five diesel

    They surely must have had some of the best mathematicians of their time, very impressive

    1. Thank you Roberto for that. Apart from being interesting, why would an engine of that displacement need five not six or eight cylinders? Since my engineering insight is poor, excuse me restating my guess that fives are a convenience for when four cylinders are too few and six too many. I know there are lots of 2.4 litre fours but they are often coarse; small sixes might be smooth but complex (are fives less complex than sixes? I think not). Are maybe fives toquier than small sixes?

    2. Direct injection and something akin to a common rail too…

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