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Dumb questions someone else might answer


#104

What ? :smiley:

If you’re talking about racing tires, that’s because they’re very soft compounds made for maximum grip. Being soft, they’re stickier to the road but that also brings much higher wear with it.


#105

No, for example, we’ve heard many things like “the Veyron’s tyres only last XX minutes at top speed” and stuff, so I’m wondering exactly what it is that is limiting the tyres from going any faster (in general)/why they burn out so quick.


#106

I’d say that’s caused by bigger forces applied to them - for high speed a car needs to overcome a very big air resistance force, which leads to more force needed to keep it moving at that speed, and all this force has to be transferred to the road through the tyres, and they transfer it by friction (more or less, I’m not a physician). More force, more friction, more wear and heat, and heat leads to even more wear.


#107

Just imagine imagine the friction the tires experience with ashphalt at 400 km/h.


#108

Oh … that i’d guess is because of centrifugal forces.

A simplified example:

400 km/h is approximately 110 m/s, so assuming your tire has a circumference of 2m [idk what actual tires have but that sounds somewhat realistic] it has to spin 55 times per second.

At the contact patch with the road, that specific piece of rubber is moving at 0 km/h while the top-most point of your tire moves forward at twice the speed of the car.

So basically, it has to withstand accelerating to 800 km/h and down to 0 again 55 times a second.


#109

I always thought it was due to the centrifugal forces as the tires try to balloon up at high speed. As it gets to those high rpms the tire wants to expand putting more force onto the ground and stretching the tire.

They sort of want to do this, which as you could imagine results in lots of forces, leading to increased wear


#110

Speaking of tires, since they lose their tread, that means the rubber is disintegrating somewhere. Isn’t it harmful for the environment or something? I’d imagine how much cars are used all these rubber particles flying everywhere can’t be good. But I don’t see it brought up at all


#111

Don’t give them ideas… it’s already hard to find sticky tires for regular cars as-is. Everything’s “low-rolling resistance” these days with the consistency of ABS plastic.


#112

It’s a source of particulates, but in the end it’s a much smaller source compared to diesel engines and burning wood for heat.

And to the guys with the friction argument, Tires heat up mainly due to the deformation of the tire, not friction.

The tire goes through deformation cycles when spinning is turning. So the faster you go, the more heat build up.

That’s also why driving on overloaded or under-inflated tires can cause tire failure, very often in the sidewall.


#113

The head gasket issues in the K-Series engine is solved putting the Freelander head gasket. I readed that is due because it was reinforced.

Put is a good car.


#114

This is the instantaneous center of velocity from the wheel


#115

@vmo

Tell me how bad of an idea is to buy a RX-8. I know it has bad mileage, anticipating to buy coilpacks and premixing and do compression tests. What more?


#116

I think the issue with RX8s is more how they’ve been treated previously, and there’s no easy way to know usually. If you beat on an RX8 constantly, then it’s pretty obvious what to expect.


#117

Is a great and reliable car if is care.

Yes. The things that you said are correct.

You need to check the oil levels every 1-2 refuel, look compression issues, and make a mod that consists in disconnect the oil injection pump that injects oil to the engine chamber, from the oil pan, and attach to a independent oil reservoir. And, now, you can put full synthetic oil in the normal carter, and in this new tank, mineral oil (like Idemitsu).

With this mod, if you forget to put oil, you only need to change apex seals in the better situation, and not breaking all engine.

If you don’t make this mod, put mineral oil (mandatory for wankels. The semi and full synthetic makes a white paste inside the chamber).

The premix… I’m not a friend about this idea, but it works. Only that I think that it could obstruct fuel injectors.

And, here, in Spain, I know a person who had 300.000km with his rx8, without issues and not opening the engine. Following the Mazda owner’s manual steps.


#118

I love the K series as much as anyone, but sadly the Land Rover MLS gasket and reinforced oil rail isn’t the magic solution. Shoddy engine buildup with differing liner protusions bugger that up in many cases, and so often the original cause of the gasket failure isn’t rectified because “it’s just a K series, it’ll need a head gasket.”


#119

Why do brands restrict colour options for higher up models? I can have a low end spec be bright green, wine red or metallic brown but if i want the top model it can be black or white???


#120

Any examples?


#121

Civic as of late is notorious for this. Get yourself a 2013 top end trim and suddenly sorry, boring colours only. No Berocca Piss Yellow and no Salaciously Scarlet for you! The Diesel came in even less colours, it was hue phobic.

I assume these colours were less popular and Honda Australia assumed that only boring people want a Civic with leather seats, ten speakers and Sat Nav. What’s even more disappointing is that with the new “refined premium” image, the Gen X Civic only comes in red, blue, grey, White, Black. BOOOOORING. I would get one if it came in Marvellously Metallic Magenta.

Other makes tend to play up the yoof doof factor with lime, electric orange, Sky blue… Ford plays that game quite well, if only I could get over my inherent dislike of their interior feel and suspicion of their build quality and fit and finish.


#122

2 words that echo in the minds of those purchasing top trims. Resale Value.
Odd color models are a hard sell. And hard sells mean wasted inventory space and price cuts.


#123

I was warned about this and still went with the odd colour :joy: Now whenever I see a Civic with the same colour, the driver and I share the nod.

Similarly custom resprays, just like modified vehicles, tend to lose a lot of money, but I would wager if you’re customising your car you’re not doing it to upsell like a professional house flipper and their makeover renos…