21-06-2020, 08:46 AM
Bob is quite right that numerous variables are at play, especially when it comes to worn components, and the presence or absence or lubricants. The way the wrench is used can also lead to variation in results. That said, a decent torque wrench used properly will give consistent and repeatable results, which is distinctly beneficial for certain parts of the car. For sure some mechanics can do that by feel, but many can't, and even the best have off days.
On the topic of modern cars Bob I'm not sure I'd use the word 'absurdly'. Critical bolted joints are nowadays individually tested on a number of samples, the results analysed statistically, and the torque range specified to guarantee the joint against yield or loosening. They are mostly designed to remain done up for the life of the car. I'm inclined to agree with anyone who thinks the quality of modern general purpose automotive bolts could be better, but the torques are generally about right and that's why you rarely find a mechanic these days going around the car with a spanner nipping things up tight.
On the topic of modern cars Bob I'm not sure I'd use the word 'absurdly'. Critical bolted joints are nowadays individually tested on a number of samples, the results analysed statistically, and the torque range specified to guarantee the joint against yield or loosening. They are mostly designed to remain done up for the life of the car. I'm inclined to agree with anyone who thinks the quality of modern general purpose automotive bolts could be better, but the torques are generally about right and that's why you rarely find a mechanic these days going around the car with a spanner nipping things up tight.