How much power do well serviced higher mileage cars lose?
Discussion
We've all seen the top gear episodes when they buy absolute dogs of cars which have lost shed loads of power but in reality if cars are driven as normal (I know this varies from person to person!) and are serviced on time with the right oils, coolant etc etc how much power do you think they lose?
I also guess this changes from engine to engine? Maybe a wheezy 3 cylinder may be shagged by 150k yet a bit V12 won't be?
But then, whilst cruising bigger engines aren't working as hard do you find they're often driven harder because of the benefits and types of drivers who own them?
Out of curiosity I'm getting mine put on a rolling road next weekend, 333hp/328bhp as standard 109k miles ago... Be interesting to see what it makes these days!
I also guess this changes from engine to engine? Maybe a wheezy 3 cylinder may be shagged by 150k yet a bit V12 won't be?
But then, whilst cruising bigger engines aren't working as hard do you find they're often driven harder because of the benefits and types of drivers who own them?
Out of curiosity I'm getting mine put on a rolling road next weekend, 333hp/328bhp as standard 109k miles ago... Be interesting to see what it makes these days!
I don't really believe it is anywhere near as bad as TG make out.
In the past I've run a few high mileage engines on rolling roads and found that they have not lost power. Several mk2 Golf GTIs with 1.8 16v, 8v, VR6s, G60s have all made the factory power or more apart from on one occasion when my 198k 1.8 16v engine "only" managed 138.2hp instead of it's 139hp it left the factory with - shocking if you ask me. I really should have contacted VW Customer service!!
Luckily for VW after rebuilding the head with new exhaust valves, new guides, new stem seals an skimming 40thou off the engine went back together and made over 150hp and as far as I know the engine is still going - I sold it with close to 220k on it.
In the past I've run a few high mileage engines on rolling roads and found that they have not lost power. Several mk2 Golf GTIs with 1.8 16v, 8v, VR6s, G60s have all made the factory power or more apart from on one occasion when my 198k 1.8 16v engine "only" managed 138.2hp instead of it's 139hp it left the factory with - shocking if you ask me. I really should have contacted VW Customer service!!
Luckily for VW after rebuilding the head with new exhaust valves, new guides, new stem seals an skimming 40thou off the engine went back together and made over 150hp and as far as I know the engine is still going - I sold it with close to 220k on it.
If the tolerances within the engine are still within spec, it shouldn't lose much at all. Carbon deposits on intake valves and blocked/dirty intake filters will reduce power though.
The only things within the engine itself that will cause dramatic power losses are if the cams have worn badly, but they'll be on their way out if they have, and if the bores are so worn that there's a lot of 'blow-by', but you'll know about that too.
With good servicing, and good quality oil, you should see very little wear even well into triple figures. The last engine I stripped had 185,000 miles on the clock and still had very good cross-hatching marks on the bores, so was hardly worn at all.
I suspect Top Gear retarded those engines they tested for the sake of making a point.
The only things within the engine itself that will cause dramatic power losses are if the cams have worn badly, but they'll be on their way out if they have, and if the bores are so worn that there's a lot of 'blow-by', but you'll know about that too.
With good servicing, and good quality oil, you should see very little wear even well into triple figures. The last engine I stripped had 185,000 miles on the clock and still had very good cross-hatching marks on the bores, so was hardly worn at all.
I suspect Top Gear retarded those engines they tested for the sake of making a point.
GuyWMD said:
Not exactly 'high' mileage, but I know that my E91 330d on 100k gave a 235.5bhp reading whilst strapped down to the rollers a few months ago.
So providing they've been properly maintained I can't see the power dropping off to the claimed levels on Top Gear.
And what's it meant to give as standard? Interesting So providing they've been properly maintained I can't see the power dropping off to the claimed levels on Top Gear.

E65Ross said:
GuyWMD said:
Not exactly 'high' mileage, but I know that my E91 330d on 100k gave a 235.5bhp reading whilst strapped down to the rollers a few months ago.
So providing they've been properly maintained I can't see the power dropping off to the claimed levels on Top Gear.
And what's it meant to give as standard? Interesting So providing they've been properly maintained I can't see the power dropping off to the claimed levels on Top Gear.

powerstroke said:
Does anyone take top garbage seriously???
Mind I suppose it's typical of most BBC output,,
No, that's why I mentioned that they're clearly shagged bangers and not "normal" cars, as such. Mind I suppose it's typical of most BBC output,,
Interesting results posted above. Will be intrigued to see what the 745i makes next Saturday.
Devil2575 said:
speedking31 said:
...don't want half the buyers returning their new cars because they don't make the claimed power?
Because new car buyers rush to get them tested?Trying to persuade the average motorist that servicing is a good idea is hard enough when a car "works" (as far as they are concerned) the thought of trying to convince them to use a dyno to ensure the engine is making maximum power is laughable.
E65Ross said:
And what's it meant to give as standard? Interesting 
Not sure, for some reason I had a figure of 231 in my head. 
It's completely standard btw! A garage I've used in the past had the RR fitted so whilst I was down for a catchup decided to see what figures it would pull out of interest really.
Gassing Station | General Gassing | Top of Page | What's New | My Stuff



ked bangers?