High mileage diesel engines. How high is too high?

For various reasons I am looking at used Q7s at the moment to replace a 2002 S6 Avant.

The petrol Q7 has the same gorgeous sounding V8 engine as the S6 but given the fuel consumption of the older car I dread to think what an extra 600kg would do to it.  As a result the 4.2TDI seems like the best option for me.

There are quite a few out there but I don't know where I should draw the line on mileage.  It will only be doing about 5k miles a year so if it was a petrol engine I'd stretch as far as 80k for the right spec but I have no idea what the equivalent is for diesels.  I have seen the perfect spec and priced car with 120,000 miles which I initially dismissed but then maybe that's acceptable in a big diesel?

If all the appropriate work and servicing has been done should this be capable of another 20-30,000 miles with normal costs or would I be taking too big a risk on some massive bills?

Any advice or experience would be greatly appreciated.  Thanks

Re: High mileage diesel engines. How high is too high?

2 years 17 weeks ago

Is there really such a thing as 'too high'? If a car has been driven sensibly and maintained to the best of standards, then I think the sky's the limit. If a car is driven badly and maintained poorly, then it's a completely different story. How a car has been driven is more important than how far. If a badly looked after car does 5,000 miles a year in stop/start traffic, it'll last much less than a car maintained well that does 50,000 miles a year on the motorway.

If you're looking to buy a high mileage car, then try going for something mechanically simple. This way, if anything does go wrong, it's cheap and easy to fix.

Where did all the replies to

2 years 17 weeks ago

Where did all the replies to this thread go?

This is a test. Please

2 years 17 weeks ago

This is a test. Please ignore.

 

Re: High mileage diesel engines. How high is too high?

2 years 17 weeks ago

Fidji wrote:
If you're looking to buy a high mileage car, then try going for something mechanically simple. This way, if anything does go wrong, it's cheap and easy to fix.
i can't imagine a Q7 V8 4.2TDI is anything but expensive, mechanically complicated and difficult to fix!!

Re: High mileage diesel engines. How high is too high?

2 years 17 weeks ago

If you only doing 5k a year you would be better off with the petrol - DPF's etc will not cope well with short runs!

Re: High mileage diesel engines. How high is too high?

2 years 17 weeks ago

The most likely items to go would be the gearbox, turbo's, injectors or fuel pump.

But a twin turbo 4.2V8 diesel lugging around 2500KG is probably only going to get 20-25mpg. A smilar petrol will probably only get 15-18mpg. Is it worth paying the extra for a diesel bearing in mind you are only going to do approx 5K miles PA.

I would stick to the petrol version, diesels when they go wrong are far more expensive to repair than the equivalent petrol version.

Re: High mileage diesel engines. How high is too high?

2 years 17 weeks ago

Dr Bunsen wrote:

If you only doing 5k a year you would be better off with the petrol - DPF's etc will not cope well with short runs!

Thanks for that, I've never owned a diesel so am totally unaware of these kind of issues. The usage will generally mean it's parked for 2-3 weeks underground, then driven 140miles, mainly motorway, and back a few days later, it will also do holidays in France so a 2,000km round trip in the Summer. It will hardly ever do a short hop.

With that usage would you still recommend petrol?

The S6 can do the 280 mile round trip on a tank, just, but the petrol Q7 is unlikely to which is why the diesel is more attractive.

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