GT6 – Oil, Engine, and High Mileage HP Deterioration Guide Introduction: There are three indicator lights in the GT Auto menu: an oil light a body rigidity light an engine light These three indicators attempt to help inform you about aspects of deterioration: the break down of the oil, the loss of the vehicle’s body rigidity, and the engine getting out of tune. When these are in ‘good condition’ the light is green. When these ‘begin to deteriorate’ the lights turn yellow. During the deterioration stages these lights transition from yellow to orange and finally to red. When the lights turn red and begin flashing GT Auto ‘recommends’ that you change your oil, restore your body rigidity, and overhaul your engine. Each of these categories of deterioration are determined by the mileage of your car since the last oil change, rigidity restoration, or engine overhaul. The purpose of this guide is to determine the amount of the deterioration on your vehicle’s HP and at what mileage the impacts occur. I am unable to make any sense of what the rigidity impact actually does because there are no numbers for this mathematician to crunch and I have never spent enough time driving only one vehicle nor have I ever been able to drive consistent enough lap times to notice measureable changes in the steering characteristics. Finally I will introduce you to a fourth category of deterioration: the high mileage engine deterioration, which has no indicator in GT Auto because there is nothing you can do to prevent or fix it (besides never driving your car ). The Quick Reference Guide: 0) Oil HP Boost: - An oil change boosts the stock HP by 5%. - The 5% HP boost lasts for 200 km. - From 200 km to 300 km after the oil change the 5% HP boost drops linearly 1% per km (i.e. 1% of the total HP gained from the boost). - The 5% HP boost does apply to whatever the current HP of the car is: so if power tuning upgrades have been installed on the car these will also receive a 5% boost. 1) Rigidity Deterioration: - The rigidity ‘begins to deteriorate’ at 500 km and ‘rigidity restoration is recommended’ at 19,500 km. - Rigidity has no influence on HP. 2) Oil Deterioration: - The oil ‘begins to deteriorate’ at 5,000 km (which also activates the oil light inside car cockpits and on the racing HUD) and an ‘oil change is recommended’ at around 6,000 km. - There is a total linear loss of 5% HP while the oil deteriorates over the 1000 km. - Once the oil has fully deteriorated, there is no more HP loss due to bad oil.t - An oil change resets the oil indicator’s ‘odometer’. - Maintaining a good oil status does not slow down or prevent the engine deterioration. 3) Engine Deterioration: - The engine begins to deteriorate at 5,300 km and an ‘engine overhaul is recommended’ at 10,300 km. - The engine deterioration continues after the recommended overhaul light turns red (unlike with oil deterioration) so that there is continued HP loss until 15,300 km. - There is a total linear loss of 5% HP while the engine deteriorates over the 10,000 km. - The engine overhaul fully restores the engine deterioration ‘odometer’, fully restores the oil’s ‘odometer’, and gives an oil change HP boost. - The oil deterioration and engine deterioration can overlap (e.g. from 5300 km to 6000 km on the odometer when no oil change or engine overhaul have been performed on a car). 4) Permanent High Mileage Deterioration: - There is a hidden high mileage HP loss that begins around 10,000 km, but may not be visible until about 15,000 km due to the low deterioration rate and PD’s HP rounding issues. - The high mileage HP loss is very difficult to calculate due to the lack of used cars like in GT5 and due to the fact that the loss may be as low as 3 or 5 % HP over a few hundred thousand kilometers: e.g. with the Red Bull 2011 Prototype, even with its massive amount of HP (meaning changes happen quicker), the deterioration is only 1 hp every 2806.8 km. - Current estimates are that a 3% loss would happen at around 130,000 km; a 5% loss would happen at around 210,000 km. - Cars with less HP will drop HP much less evidently and the issue with the way PD rounds HP makes accurate predictions exceptionally tedious. - The high mileage HP loss has no indicator light in GT Auto because this HP is a permanent loss, unlike the oil deterioration and engine deterioration HP losses which can always be fully restored. - The loss is permanent: unless PD releases Car Restore Tickets that reset mileage to zero in the future like they did in GT5. - This loss is unlikely to impact most players since there are no more used cars and most players are unlikely to put 10,000+ kilometers on their cars very often. Also every car can be purchased new besides Anniversary Edition cars. Caveat: The GT Auto indicators will not turn on at the same mileage for each car. There will be variation between cars because of the way PD rounds HP. In other words even though Engine Deterioration is happening to a car, the amount of deterioration may not be high enough for the HP to change enough to trigger a light; or the car’s stock HP may be a hidden fraction value such that the HP gets rounded down sooner than you would expect when multiple deterioration types are occurring at once. The lights also often trigger before any HP change is visible to the user. So keep in mind that some variation between cars is to be expected. There will also be variation in mileage for any car that has participated in online races with tire wear turned off. Although mileage is gained, the deteriorations are not impacted. The deteriorations function normally when tire wear is turned on. This issue means that cars will appear to trigger the gauges later than expected because there will be extra mileage on the car's odometer that occurred while the deteriorations were frozen. Note: All information and data is based on the 1.03-1.04 version of the game.