Hot answers tagged

20

tl;dr: Sadly, that tire appears to be a goner. The wheel is likely fine, though. You might be able to replace just the one tire. If you look at the divot cut out of the side of the tire, you'll see a distinct color and texture difference in that center portion. It appears that you've removed all the surface rubber in that area. All of the insulating ...


19

I really think that it's more of a naming convention issue but there is a marked difference between 4x4 and AWD. In 4x4 all the wheels are "guaranteed" power. Power is sent from the engine to the transfer case and then the transfer case sends it to the front axle and rear axle. The reason I put guaranteed in quotes is because there is such a thing as full ...


11

It says right on the webpage: Conventional all-wheel drive cars employ complex mechanical linkages to distribute power from a single engine to all four wheels. This sacrifices efficiency in favor of all weather traction. In contrast, each Model S motor is lighter, smaller and more efficient than its rear wheel drive counterpart, providing both improved ...


11

Does anyone have a definitive answer as to which option I should choose? I do: you need matching tires. That said, it's your car and you have to make the decision. I'd tend to replace all four. @Paulster2 also makes a good point that you could shave down a new one to match. Let's start by looking at one of the most useful paragraphs from the Tire ...


11

My first thoughts, given the car is question, would be to check to see if there is a performance version of the car which features four wheel drive. For road use, if you have over 300bhp going through the front wheels, things can get difficult. A friend of mind had a 320bhp Seat Leon Cupra (Front wheel drive) and sold it to buy an Audi S3 (same basic ...


11

One of the things the other answers neglected to mention and is probably the key point between AWD and 4x4 is that AWD transfer cases will almost always be a single speed differential. The 4x4 will almost always have 4-wheel high and 4-wheel low ranges and be selectable. This provides more torque if the driver deems the situation to need it. 4x4 may also ...


10

They likely do hold some liability, since they should have known that an AWD should have matching tire diameters across all tires. They may argue that you hold some responsibility since the Impreza owners manual makes this pretty clear: . You must install four tires that are of the same size, circumference, construction, manufacturer, brand (tread ...


8

Based on your picture I would replace the tire without question. It's not worth the risk. If the sidewall fails while driving it could result in you losing control of the vehicle.


6

See Is it OK to replace only 2 tires on an AWD car?. If you call different Audi dealers you're likely to get differing answers regarding how much tread depth difference is OK for the all-wheel-drive system. Nonetheless, I would advocate calling to get specific recommendations for your vehicle, as some all-wheel drive systems are more sensitive to ...


6

Please take the following text with a grain of salt as this is just an interpretation of a complex problem from a random dude on the Internet The steering angle sensor issue (DSC) is the most dangerous (and probably expensive) issue as your road safety depends on it. Perhaps it is caused by the later mentioned electrical issue, but this is something ...


5

It matters, but how much it matters varies from vehicle to vehicle. TireRack has an article about this topic -> Matching Tires on Four-Wheel Drive and All-Wheel Drive Vehicles Here is the Manufacture Specific info from the end of the article: Here are recommendations from some of the manufactures that Tire Rack currently serves for matching the tires ...


5

Before you start, I'd have a good read of the rules applying to it - I seem to remember that Germany is very strict on heavily modified cars, so you might well find there are restrictions on what you can do to it - modifying the monocoque (chassis/bodyshell) to allow the fitment of a propshaft and rear drive axle might well be restricted, or involve huge ...


5

This is pieced together from articles about this and the talk we had from a Tesla rep at the car leasing company I work for. The improved range of the dual motor setup arises from the front and rear gearboxes (one per motor, nothing interlinking them) having different ratios. Electric motors have a rpm range in which they operate most efficiently, having ...


5

Replace the tire by all means. If you drive around with a tire damaged that badly, you risk having it explode while you're driving and losing total control of the vehicle, and possibly being stranded on the side of the road while you wait for towing. Here's a mathematical formula: Cost of (waiting if it explodes + towing + new tire/car) > Cost of new ...


5

It looks as though the boot has split and is spewing grease all over the place. If there isn't a lot of dirt let into the boot, you should be able to just replace the boot (yes, this is a chore, but a heck of a lot cheaper than replacing the half-shaft). When you replace the boot, you'll want to put some grease back into it to supplement what was lost. If ...


5

The short, easy answer: heat. That energy is being converted to heat in the driveline components for various reasons. It's important to note that these numbers are aggregates, however, and a really high end well engineered AWD or RWD system could outperform a cheaply manufactured FWD system. Differential losses tend to be considerably larger, especially ...


4

Short answer. Yes. Your vehicle could be pulling to the right for several reasons. It could be uneven tire wear (which would likely have been caused by an alignment issue), tire pressure (which you've checked), wheel damage (which you've checked) or misalignment. One thing you might try before going for an alignment is making sure that all four of your ...


4

Jerking and thumping when shifting through gears is an indication that you have bad either: bad engine mounts bad transmission mounts bad differential mounts bad axles a combination or all of the above Shifting into neutral does relieve the "tension", as you put it, but you need to care care of these issues. They can end up being costly.


4

4WD has the best traction in off road conditions, which is mainly what most larger vehicles are used for. As well as this, 4WD offers better fuel economy which is generally more favorable in a larger vehicle as these will already have a greater fuel consumption due to their added weight. You are correct about AWD being at least as good in conditions such as ...


4

There is no fundamental reason for RWD to be less fuel efficient than FWD. There are many advantages to FWD, fuel efficiency is not a driver. Most rear drive cars these days are sport(y) , performance , luxury, or SUV's that are not optimized for maximal fuel efficiency. That is the reason you will typically see lower economy numbers. AWD is another matter ...


4

Your premise is wrong. The main reasons FWD cars are more commonplace today are: easier assembly: the entire drivetrain goes into the chassis as one complete assembly. unibody construction: FWD cars don't need a transmission and driveshaft tunnel under the car, making the unibody construction optimized for its own sake.


3

It's unlikely that 2WD will save you a lot more fuel than AWD but it will save you more than zero. 2WD will definitely save you fuel over the 4WD Lock setting. The reality is that, no matter what setting you use, the engine still has to move the same mass of metal down the road. I.e., maximum efficiency is bounded. That said, in 2WD mode, you are avoiding ...


3

Typically part time 4WD is not the same as AWD. Part time 4WD will actually lock the front and rear axles together, not providing a differential between them to handle the speed differences between front and rear wheels while turning. As such driving a part time 4WD in 4WD on pavement is a great way to break things. Auto is intended to give you 4WD when it's ...


3

The general consensus on this is that it depends where you are intending to go - you want something that is common in the local area so that parts are readily available. The two standard choices are Land Rover (either Defender or Discovery) or Toyota (LandCruiser or Hilux) - Land Rovers tend to be more common in Africa, Toyotas are more common in Asia. Both ...


3

I've heard it many times, but never seen any proof. See the question and my answer to this post. I have never read about it in any of the Factory Service Manuals I have been through, so I shelve it up as false. I think the idea is that new fluid, with all the fresh detergents, shock dirt and debris loose and cause problems. Again, never seen it happen.


3

"It depends"... I've historically opted to replace all 4 just to be safe (on my AWD with 3 LSD beast, on the RWD open diff I replace 1 at a time if needed :-) ). In theory a small difference won't blow up the transfer case or the diffs (there's always at least a TINY difference anyways). Normal wear with a normal rotation obviously doesn't violate the ...


3

At 1900 miles, you'll only need to replace one tire. Make sure the new tire is IDENTICAL to the other three. Ask the shop to measure the tread wear on the other tires, and to shave the new tire if the difference is outside the limits allowed. I think at 1900 miles, you won't even need to shave it. If the tire replacement shop gives you a strange look when ...


3

It's difficult to reach a conclusive answer, but you're on the right track with the extra mass of a RWD transmission - the propeller shaft taking power to the rear wheels adds some considerable weight. The gearbox is also traditionally attached directly behind the engine, and this means it impinges on the passenger compartment. A tunnel has to be constructed ...


3

Here are my observations (kudos to Myself for providing translations): DSC: Lenkwinkelsensor Versorgung [Steering angle sensor power supply] LWS: Schleiferfehler (Ableichbetrieb) [Slider error (calibration)] It seems that the steering angle sensor is not being supplied power as it should. This error was set about 500 km prior to the vehicle's ...


3

The center differential in a typical Subaru transmission is housed inside of the main transmission case. For the MT models, these are typically viscous-coupling that control the torque split between the front and rear differentials (which may be open, viscous/clutch/Torsen LSD, etc.). The AT models may have different things that function as a center ...


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