Transitional models are fascinating. Depending on your point of view, they can be either seen as a car’s best variant, or a sort of chimera that lacks proper character. What is a transitional model? Several definitions could fit, but let’s take a relatively clear-cut one, such as a new body with the old engine (or the other way around). A few examples that would come to mind might be the Jaguar 420, the DKW F102 or, you guessed it, the Triumph TR5.
The TR series of roadsters was Triumph’s calling card. They started with the TR2 in 1953 – the first roadster to be able to hit a true 100mph for less than £1000 – and continued with the TR3 in 1955, which had a 100hp engine and introduced disc brakes to the British public. The TR4 arrived in 1961, featuring far more modern styling by Michelotti, a 4-cyl. engine upped to 2.1 litres and, from 1965, a rather sophisticated independent rear suspension.
Standard-Triumph, owned by Leyland since 1960, were determined to match arch-rival MG in their race towards the ultimate British roadster. The other BMC entrant was Austin-Healey, but those were clearly going to disappear soon, so BMC figured that they would just shoehorn the heavy 3-litre Austin engine into the MGB to take over from the Big Healey, creating the MGC. Triumph could not let that go unanswered.
If MG were simply going to add a 6-cyl. to their roadster range (but keep the rest of the car more or less unchanged, except the ugly bonnet bulge and the front suspension), why should Triumph not follow suit? The TR4’s styling was still pretty fresh, its suspension was leagues ahead of the MGC.
The issue was to develop a suitable engine. The Triumph 2000’s 6-cyl. unit, inherited from the Standard Vanguard, was the obvious choice, but at just 1998cc and 90hp, it was a tad too small. The solution was to add a half litre of displacement, improve the camshaft and, icing on the cake, give it fuel injection (or “petrol injection,” to give it its proper British idiom), courtesy of Lucas.
The name Lucas strikes fear in the mind of most enthusiasts. Maybe that’s why it was omitted from many adverts at the time. But that’s the infamous Lucas electrics, surely. Mechanical petrol injection is a different matter, no? What with their impeccable racing pedigree (Lucas P.I. was used on Jaguar to win Le Mans in 1956 and especially 1957, where D-Types won 1st, 2nd, 3rd, 4th and 6th place) and use in Maserati production cars, wasn’t the Lucas system just as good as Mercedes-Benz’s or Kugelfischer’s?
The Lucas system used in the TR5 was the new “Mark 2” petrol injection, so it was pretty different from the one seen in Jaguars and Maseratis. It was also simpler and cheaper than the aforementioned German systems, which helped keep the TR5’s price in reasonable territory. Did it work well? Apparently, it wasn’t too bad, but it did suffer from a few niggles, some of which could be remedied by replacing the Lucas fuel pump by a Bosch one. Still, ancient mechanical fuel injection setups like these are tricky to sort out correctly nowadays, so quite a few TR5s have since been retrofitted with carbs. Maybe Triumph’s US customers dodged a bullet with that one.
The Mk 2 Lucas Petrol Injection was not certified for American emissions controls, so the system was never used in cars headed over the Pond. Known as the TR250, those were carburated from the factory, providing a modest 111hp when the TR5 P.I. boasted 150hp (though the true (net) number is 142, but let’s keep that between us).
The dash was given a thorough refresh as well, mostly in the for of safety padding and the like. It’s not looking particularly well preserved in this car, but then the Triumph was built to a price. And the MGC was not especially luxurious either. A few rungs below Jaguar, certainly.
Contemporary tests all praise the TR5’s handling and power, though it is said to be rather twitchy on wet roads – the chassis was perhaps a tad overwhelmed by the power and mass of the new six. But they also claim that the Triumph is a lot more usable and fun to drive than the nose-heavy MGC.
Of course, all this one-upmanship with MG was all for naught in the end, as Leyland and BMC tied the knot and the former rivals became awkward stablemates, even as the TR5’s short production run was finishing. With just under 3000 units made in a 13-month production run in 1967-68, it’s easily the rarest of the TRs. And thanks to its classic looks and punchy engine, probably the best of the breed.
The TR5 served its purpose as a test mule for the P.I. straight-6 until it was replaced by the heavily restyled (and somewhat less visually appealing, in my view) TR6, which also ended up being a smidge slower than its predecessor. Clearly, the TR had peaked at number 5.
Related posts:
Curbside Capsule: 1967 Triumph TR250 – May Your New Year Be Triumphant, by Joseph Dennis
Vintage R&T Road Test: 1967 Triumph TR-250 – Where’s Our TR-5?, by PN
A very nice example, and well maintained because the rear wheels are vertical.
Although the 5/250 is the most capable of the TR’s I remain enamored with the TR3A/B and TR4.
A problem for USA new car buyers was after shipping, importer mark up, and dealer markup, a TR250 cost more than a Pontiac GTO… and sportiness/comfort?
0 – 100 MPH: TR250 @ 40 seconds… GTO @ 13 seconds…
I still have my 1975 MG Midget, but engines and transmissions were going kaput at about every 25K miles, so it now sports a Buick 215″ aluminum V8 and B-W T50 5 speed manual…
I never saw this as a response to the MG-C, but simply a natural evolution of the TR line. Unlike at MG, which very much kept the MGB, the TR-5 fully replaced the TR-4A, with its rather hoary and rough big old four.
I had a TR-3A, TR-4 and a TR-6 All in an attempt to get more modern, comfortable car, as in those days this was my daily driver. The 6 kept me the driest and had the best seats.
For what it’s worth, just to give some meaning to the value of the pound sterling in 1953 compared to the dollar in 2025, according to the website, Currency Converter, if the 1953 price of a TR2 in 1953 was 990 pounds, its 2025 cost in dollars would be $45,173.34, and if its cost was 950 pounds, then its 2025 cost in dollars would be $43348.16, and if the 1953 TR2 actually cost 1,000 pounds, then its 2025 cost in dollars would be $45,629.64.
Until the early ’70s, the dollar and the sterling exchanged at a fixed rate, which was $2.80/£ from 1949 through 1967 and then $2.40/£ from 1968 on.
It’s important to remember, though, that imported cars’ U.S. prices were not on a straight exchange basis. The list price of a the first U.S. TR2 in late 1953 was $2,448 FOB. The last U.S. TR4A, without independent rear suspension, was $2,899 FOB.
Had 2 TR4as and a green-gray with (white cross-bonnet stripe) all original TR250 that came to me from NC owned by a Captain at Ft Meade. Body was mint but the head was off needing work. Flipped it fairly quickly but should have finished and enjoyed it for a while first, rare and desirable now. The torquey TR 4 tractor engine cars were crude but fun, the 2500 6 TR-6 smooth and silky in several that I got to drive.
The C series 6 cylinder as fitted to the MGC was actually a Morris engine, not that it makes any difference to it being a dud, too heavy and not very powerful.
In Australia there was a 6 that was a B and a half, I don’t know if it was any good, but “not invented here old chap.”
Neighbours 3 doors away at the end of the 1960s had one of these. They often arrived back from a trip without the TR which had broken down somewhere.
UK market TR6s were eventually detuned to 125 rated horsepower with the Lucas injection in the name of dependability, so I wonder just how chancy the installations in the TR5 really were. It is worth noting that the US market was the one that really mattered for British sports cars, and they chose not to risk alienating their most important customers with the fuel injection system.
I’ve always been amazed Triumph moved to fuel injection on these. It was the kind of thing associated with real exotics back in ’67. And here was Triumph putting it on the TR, and in their top saloon as well. Even as a kid I knew this was Special. And from Triumph! You’d kind of expect it from a company like Aston Martin or Jaguar, but they were still using carbs. Triumph!
From what I’ve read, working on it required specialist knowledge though – which they (perhaps wisely) figured made it unviable in the US. And yet we got the full-fat setup here in Australia! Empire preference? A slight on US mechanics? Or did they suspect there might be bugs that would only become evident in service? Who knows!
They were concerned about the ability of the PI engine to pass U.S. emissions standards, and the U.S. sales organization was also very uneasy about the impact on the price.
I don’t believe that for a second. Alfa Romeo adapted mechanical fuel injection for their US models during 1968 for the exact reason that they were unable to meet US emissions standards without fuel injection, which more than one importer found to be impossible with 2 barrel side draft carburetors. Emission standards are what ultimately confined carburetors to the history books.
BMW also developed the 2002tii because they could meet emissions standards with mechanical fuel injection while they couldn’t with their twin-carbureted 2002ti.
The 2.5 PI engine was a very different animal than the Alfa twin-cam or BMW 2-liter four, and the challenges it posed vis-à-vis emissions were not the same. (Also, the Lucas Mk2 system is not the same as the Alfa Romeo SPICA system, nor is it the same as the injection system in a 2002tii.)
That said, I think that the U.S. importer’s unease about the price was probably more decisive. This was the same organization, recall, that insisted on making the independent rear suspension an extra-cost option on the TR4A because standardizing it would have pushed the base price over $3,000, which they regarded as an important psychological barrier in this class. Since the U.S. accounted for the very large majority of TR sales worldwide, the factory was inclined to take their feedback quite seriously.
Until now I never knew that the TR6 had a different grille than the earlier models, all models were grouped as TR6s in my mind. The TR 5 or 2.5 is definitely better looking in the classic style. One thing that I liked about these Triumphs was that they have big wheels. I don’t know if they are 15’s or even 14’s but they look just a little too big, which is just right. I never really considered owning one of these cars, an old Cadillac convertible suited me better. When I got around to owning a sports car I went with Datsun Zs, a superior car, in my eyes.
The Triumph that really caught my eye is the diminutive Spitfire. A co worker gave me a ride in his, and I thought that it was delightful, though I wouldn’t have used that word when I was in my twenties! Those always struck me as a mini Jaguar E Type.
What a beautiful car .
I have always liked this Triumph body style, I have very fond memories of an unwanted and poorly repaired after wrecking midnight blue TR4a in 1972 .
Many are not aware that most manufacturers in the mid 1960’s were experimenting with mostly electronic fuel injection because that was the fastest and cheapest way to make the legacy engines emission compliant .
Some systems (BOSCH D-Jetronic) were crude to a fault bu the writing was on the wall as they say .
-Nate
You would think so, but when Bosch went around Europe in 1964 to pitch its electronic injection system, only Volkswagen was at all interested, and that was due mostly to one Volkswagen management executive who thought it was a good idea. It really wasn’t until after VW had taken the plunge that anyone else was willing to get onboard. There were some mechanical injection systems in Europe — Mercedes had been using various Bosch mechanical indirect systems for a while, and Lucas, Kugelfischer, and SPICA developed their own — but the reaction to electronic systems was, according to Bosch’s account, grave suspicion.
There was very little automaker interest in the U.S. either. Ford talked to Bendix about the possibility of modernized EFI for the Continental Mark series, along the same lines as the subsequent Bendix system used by Cadillac, but Bendix kept shooting themselves in the foot because their senior management didn’t want to spend any money on fuel injection unless it was being underwritten by a customer. Since Bendix had very broad patent protection on electronic injection technology, they really squelched its further development for years.
There were some articles in the car magazines and trades saying automakers SHOULD be looking at electronic injection as a means of emissions compliance, but actual interest was quite limited until the ’70s, and even then, many automakers clung to carburetors for years and years.
I’ve driven a friend’s U.S.-spec TR250, and it’s loads of fun in a traditional-slow-car-fast sort of way. Not terribly quick by today’s standards, but what power it has comes alive at low revs. With nice, balanced handling, it’s a perfect car for winding back roads when the sun is out.