To be fair to JohnF, its not that different from more modern cars. I cannot speak for the turbocharged ones, but for my normally-aspirated Mazda3 1.6 petrol (late 2005 build), it says (roughly - I can't be bothered to look in the manual at the mo) that don't exceed 3k rpm, don't run in for long periods at constant speed/revs (i.e. all motorway driving) and try and run it through all gears and revs up to 3k rpm for the first 1k miles (it could be km [600 miles ish]).

I personally didn't find that particularly restrictive, although I did change my route to my workplace at the time for 3-4 weeks to go on more 'ordinary' roads than mainly using the motorway.

It did actually say that the oil should be changed then as well, presumably to get rid of any initial wear/small deposits left over from manufacture, then at 1 year/12k miles as usual. I did ask at my dealership and they said this wasn't necessary (confirmed by Mazda UK).

The best advice on this is in the Ask HJ section of this site, under FAQs.........

There is better and more succint advice in my TR7 Handbook......

'Avoid placing heavy loads upon the engine, such as using full throttle at low speeds or when the engine is cold. Running-in should be progressive and no harm will result from the engine being allowed to 'rev' fairly fast for short periods provided it is thoroughly warm and not pulling hard..........full power should not be used until at least 1000 miles have been covered, and even then it should be used only for short periods at a time. These periods can be extended as the engine becomes more responsive'.

But that was written in the late 1970's, 40 years ago. Much has changed with materials, oils and manufacturing techniques in that time.

No it hasn't. Materials and oil are fundamentally the same. So are the techniques. Tolerances have improved slightly but I do not think pistons and their rings are any tighter in the bores than they used to be.

When that was written an oil change at 500 to 1500 miles was included in the vehicle price for 2 reasons, the oild would be full of metal particles and the oil was designed for "running in".

This is nonsense. Even if there were a few particles, they would be removed by the oil filter, a standard piece of equipment since before we were born. But I agree 'running in oil' is usually no longer necessary - but that doesn't mean a modern new engine won't benefit by the above TR7 handbook advice.

Comparing your TR7, a car with an engine not known for its reliability with a modern small turbo petrol is not relevant.

I wasn't comparing. Or contrasting. I was merely offering what I think is better and more easily understandable running in advice than HJ's. And actually, the Triumph slant four is fundamentally a reliable and mechanically robust engine - otherwise Saab would not have used it (and neither would I). The early ones had an unreliable water pump which surreptitiously leaked. Combined with the lack of water coolant level alert, this could result in overheating and CHG failure if undetected - as would occur in any engine.