[Remi]

My husband recently started driving my 2013 1.3 Toyota Auris as his own car a 1.9 died after Xmas. He consistently drives at high speeds @ 80/90+ even though I have asked him to slow down as the car was just used to myself and my daughter driving it.

At Easter, I had to get a new clutch. Few weeks later, warning light and mechanic says it needs new catalytic converter and oxygen pump! Last evening, my husband says, theres another noise in the car. Think it might be a bearing!

I know the car is 12/13 years old, but the mechanic told me last summer, this is great little car, going well.

So, am I wrong in thinking these recent major problems are being caused by the dramatic change in driving style.

Any advice would be appreciated.

[Rolebama]

On a personal note, I think engine wear is more consistent with engine speed rather than road speed. Cars are nowadays quite highly geared, so the speeds you mention are probably maintained with relatively low engine speeds. As to other bits and pieces wearing out, there does seem to be a correlation between speed and wear, and to be fair, it is quite common for a change of use to speed this up as well. You have not mentioned the mileage the car has done. This will also effect the wear rate.

[Drivingforfun]

In a vacuum I think that's right @Rolebama but if fuel economy takes a disproportionately higher hit per 1 mph increase in speed at a higher speed, would that suggest the engine is working disproportionately harder?

I have little knowledge of how an engine works so not sure the implications on an engine of 3000RPM while idle vs 3000RPM attached to a drive train pulling weight

[olduser]

At higher speeds there is an increase in stress on the whole car but in most cases, unless trained otherwise most 'fast' drivers tend to be less sympathetic to the car, so they setoff with higher revs, increasing transmission, and clutch loads they tend to brake harder and more often.
This all adds up to higher loads on the suspension.

Looking at the age of the car it is due a major refurbishment.
Whilst being driven by ladies (who tend to be less aggressive) many parts would be slowly dying of old age but now being forced to work harder they will just fail.

There is the other effect, when someone drives the same car over a long period, they adapt to the wear and failures, they go unnoticed.
Someone new to the car will notice them.

[Rolebama]

Within the rpm range there is a part where the engine is 'comfortable'. If the revs are too low this can put a higher load on the engine than running flat out. We all seem to accept that running flat out is harmful. This is not necessarily true, it is down to the design of the engine. The most harmful scenario is labouring a cold engine.
As to mpg, all the above holds true. Although aerodynamics also come into play at higher speeds.
In terms of clutch, brake and suspension etc wear, they are all designed with a massive safety factor built in, so they should be perfectly capable of working within the performance of the car. The only real-world problem is the fitting of sub-par third party replacement parts.
The only component of the car that really affects all the above is the nut behind the wheel. If there is a loose screw in there, all the above becomes null and void. 😁