Tbred911

well... those people who track eventually end up having issues over a 4 year period... especially if your doing like 15 track days per year... tracking is hard on the car... causes oil starvation and bearing wear and high temps etc...

I think the impact is indeed *significant*...

chsu74

+1. Engine life probably can be approximated into how many revolutions it turns; extended by the frequency of oil changes and other maintainance measures.

When you run on track at 5k rpm and above, it is a little bit different than purring on the highway in 6th gear at 2800 rpm. This is not even mentioning the extra stress you are putting on the components at the higher RPMs.

schwank

Actually if you talk to Jake Raby, he sees LESS instance of failure, particularly IMS, in engines that run at higher sustained RPMs.

chsu74

Therefore, your logic implies that your car will last forever if driven constantly at 7,000 rpm without stopping? I will take this bet anyday.

I believe Jake is implying that the engine will fail less often not that the engine will run forever.

pongobaz

You do realize that these cars are built in Germany where there is no such thing as purring along at 2800 rpm on the autobahn? Doing a dozen trackdays a year here, would be the equivalent wear and tear of two weeks of commuting to work for the average German. These cars are engineered for sustained high rev use.

medtech

Sounds logical to me.
Personally I would think that it is mostly oil starvation in hard corners and the extreme pressures caused by WOT hundereds of time per session. Hard acceleration will cause stress on the oil as well as the seals.

chsu74

Not every single paved road in Germany is without speed limits. Heck ,there are only certain parts of the autobahn that have no speed limits. Germany is now considering implementing speed limits on autobahns.

Macster

of my info. But IIRC a modern gasoline engine as a useful life of something like 10,000 hours.

How you use car, drive car then depends upon how many miles you get out of car. If someone uses teh car in such a way the average speed over those 10,000 hours is 15 miles per hour then then engine's reached that 10,000 hour running time at 150,000 miles.

Average 45mph and 10,000 hours is 450,000 miles.

Hard to average 45mph with much city driving.

I'm amazed when I record my driving in a data logger and review it or monitor my driving with an on-board computer or GPS device and note how just a few minutes of city/stop and go driving, just idling on the gas station apron while I note odometer reading, trip odometer reading, etc. before moving off, how much highway driving at legal highway speed is required to bring that speed average up to anywhere near even 60mph. When I'm really careful and keep my idle and slow speed driving at bare minimum and get back on the freeway as soon as possible I can sometimes get the average speed to pretty close to the legal limit. But just a short stop sees that speed average drop like a rock.

Those "tests" where an automaker decides to run a car on a closed track for say 100,000 miles at a high speed. Those are easy on the car. Cars are allowed scheduled vital fluid/filter services and save for those and pitstops to fuel and change drivers, see fairly constant engine loading. Sure high rpms, but oil is fresh, at high pressure (no cold starts, etc.), and engine and oil at operating temperature always.

Tracking is hard on a car. Engine is being asked to deliver near peak output much more frequently. Engine being subjected to high heat load and high mechanical stresses. Good engine maintenance (fresh oil/filter) can help prevent trouble from older less fresh oil breaking down under these conditions, but can't protect the engine against mechanical stresses.

That an engine lasts as long as it does when being tracked just shows the amount of margin these engines have. One can use that margin to drive 450,000 miles over the years or track car x number of sessions per year for y years.

Chances are the tracked car will get moved on before margins are used up so whoever buys that car ends up suffering the depreciation tracking a car subjects the car to.

I'd never buy a tracked car.

Sincerely,

Macster.

chsu74

^ I think this info is quite right on highway mile useage. The car service I use that make airport runs typically logs around 100K miles per year. I have seen towncars with over 700K miles on the clock and continue to run beautifully.

I have never seen a NYC taxi with over 150K miles that is running on all cylinders smoothly.

pongobaz

I know, I lived in Europe for years and visit frequently. Last time I was there, my rental A3 TDI sportline was flat to the floor along with other less "worthy" vehicles on the 'bahn whenever it was possible and legal to do so. Little old ladies will go flat out in 20 year old Opels over there. In NA we drive like pussies and think our p-cars are made of glass held together by fairy dust.

Tbred911

well... not quite... you don't experience the g-forces and cornering and braking you do on the autobahn... authobahn is all strait line driving... big difference... highway driving as well... its easy on the car... unless your going 180 MPH sustained for like 20 minutes a day ... but I don't think you can do that speed for that long in Germany... also high speed driving gives your car serious cooling vs tracking where you are constantly braking and accelerating... I too would never buy a tracked vehicle...

Tbred911

I believe over the long term the average speed of all vehicles is approx 30 mph... of course this applies to vehicles used on a daily basis... its a way of checking to see if the odo has been "rolled back" by some unscrupulous seller... mileage / engine hours ~ 30 mph... if its off by much then you know its been tampered with...

porschedog

37 miles at most. That's all you'll get. Really. I keep a spare in the boot and buy extras on ebay.

ElTorrente

I rarely purr along at only 2800rpms. I consider less than 3000 to be almost lugging the engine. When my rpms are less than 3000, I put it into 5th gear. I've conditioned myself to avoid any low rpm/high gear combination.

Tbred911

huh? you put it in 5th gear when rpm>3000 ? is that not a low rpm/high gear combo?