Age and its relation to loss of HP?

[seismic22]

Hi,

people often say to me, "oh that car is meant to be running so an so horse power but of course its not now ,prob a fair bit less as its old now" etc etc etc

Is this really true?? Im of the current belief that as long as a car has always been maintained well and is currently not due for a service etc its HP output should be hardly if any less than what is was new, especially with some engines that when loosened up actually gain horsepower??

I have heard of numerous cars (recently a couple of p10 primera eGT's and e36 328's) putting out significantly more hosrepower when dynoed at around 100k than what they were when they were new.

Any thoughts?

[slomax]

I hope it doesn't go down severely. My engine only had 29hp new and its getting on 30 years old.

[intrepid44]

Parts wear out, tolerances become greater and therefore more energy is lost to forms other than powering the car.

Edit: Also there are many othe factors to include, dyno's not being accurate and not knowing the true bhp of the car when new.

Edited by intrepid44 on Tuesday 6th April 15:59

[Rawwr]

I think many of the horses that came with my Mondeo have since been turned into glue.

[Great Pretender]

MKII Golf GTIs were renound for making more power than when new as their engines past the 100k mark.

With correct mintenance, I don't see why a miley engine wouldn't at leat retain 95% of its original power.

[JB!]

not always the case.

i was at the clubpolo rolling road day and watched my friends H-plate polo gt make 14bhp more than factory with just an open cone filter and a decat, when other higher spec engines were making less.

all depends on how its been looked after IMHO, and GT's are high compression, perhaps higher mileage (his was 140k!!!) loosens them up nicely?

[aka_kerrly]

i dont believe it. If a engine has been well serviced it should produce the same power, if anything in my experience the higher millages allow engines to losen up a bit and produce better power.

my golf GTI had lost 0.8HP ATW when it was rolled on 199k and was on 1hp up when rolled on 215k - bog standard engine apart from a K&N panel filter.

On one occassion we ran 4 mk2 golf 16vs one standard model, 3 modified with exhaust/air filter/breathing mods and all the engines were circa 110-150k. modified ones put down 20Hp more than standard which put down 10hp more than factory all within a few min of each other.

dave

[Crusoe]

watch the topgear bargain Italian supercar program, think after 25 years most had lost 40% or more of the headline figure though that may have been tall tales from the manufacturer to start with.

[Dan_1981]

Crusoe said:

watch the topgear bargain Italian supercar program, think after 25 years most had lost 40% or more of the headline figure though that may have been tall tales from the manufacturer to start with.

And all three of them broke down before the end of the program.... not exactly good examples of well maintained cars.

[louismchuge]

Crusoe said:

watch the topgear bargain Italian supercar program, think after 25 years most had lost 40% or more of the headline figure though that may have been tall tales from the manufacturer to start with.

and Top Gear is an entertainment show, not really factual in many ways

[Rawwr]

Crusoe said:

watch the topgear bargain Italian supercar program, think after 25 years most had lost 40% or more of the headline figure though that may have been tall tales from the manufacturer to start with.

Yeah, but consider the engines in those cars were cobbled together in a shed by old Italian men, between stuffing handfuls of pasta into their faces and drinking really cheap wine and olive oil, compared to modern engines which are meticulously assembled by R2D2's autistic grandchildren.

[ExPat2B]

doogz said:

aka_kerrly said:

my golf GTI had lost 0.8HP ATW when it was rolled on 199k and was on 1hp up when rolled on 215k - bog standard engine apart from a K&N panel filter.

says who. The dyno? Oh, well it must be true!

I don't believe that the engine was making more power after 215k miles, than it was after say, 20k miles. There are so many things that can affect performance on a rolling road, the most obvious being how well the set up is calibrated, but also what the weather is like, and what size/if they use a fan etc.

at 215k miles, a very rough calculation shows each piston will have moved up, and back down, around oen billion times. No matter how well that's lubricated, that'll wear. The bores will inevitably get worn over time. This can be good to a point, the engine can loosen up, but eventually, you'll start to loose compression. Engines will not last for ever, no matter how well you look after it. Fact.

Actually, I have opened up several modern high mileage engines, and there is absolutely no wear on the bores, and the hone marks are still visible. Likewise the Cam/tappet tolerences have still been at the minimum when I measured them. 200K is no problem whatsoever for a modern engine. The only wear I could really see was scoring on the bearing surfaces and oil pumps, but nothing that would affect operation of the engine.

I do agree with the Dynos being optomisitc. All them have a signifigant fudge factor where they try to guess the flywheel value by adding the transmission loss back in, and the operators know what people like........

Edited by ExPat2B on Tuesday 6th April 16:35

[seismic22]

So probably the answer is if a car is maintained throughout its life it should lose hardly any hp if any at all and there is a good posibility that it could gain a small amount from the engine loosening up. right?

[MondeoMan1981]

So are you guys saying I might have less than my whopping 68bhp......

[dylan0451]

i think what people are saying is that dyno operators are aware people want to be impressed, and want to feel their money has been well spent - temp sensors on warm equipment, odd sae factors, 25% transmission losses etc.

i'd take the wheel hp, as measured and not be too concerned about a flywheel estimate

[Mr2Mike]

With the advent of EGR, I can see higher mileage engines losing power as the intake manifolds and ports get clogged up, especially of diesels.

[TomJS]

Dan_1981 said:

Crusoe said:

watch the topgear bargain Italian supercar program, think after 25 years most had lost 40% or more of the headline figure though that may have been tall tales from the manufacturer to start with.

And all three of them broke down before the end of the program.... not exactly good examples of well maintained cars.

All carbs as well - wonder how well set up those 'stellar' examples were.

[dylan0451]

i wonder what 'oil' clarksons (?) one was on when he bought it, sawdust ?! it didn't take too well to the change

[seismic22]

I unfortunately now consider cleaning egr's and inlet manifolds as part of normal servicing for any cars with them! Not every 6k or 12k but certainly every 40ishk a good clean is needed really, espcially on the dirty diesels!

[Fox-]

I think its a load of rubbish to be honest.

My car rolled off the production line developing 231bhp.

5 years and 150,000 miles later, I reversed it off the rolling road having just recorded 232bhp.