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Thursday, 26 January 2012

How To: Buy A Second-Hand Car

Buying a used car? Be careful. There are lots to consider when buying used. It's not just a question of mileage, but more a question of 'who's owned it?' and 'what's it's history?' and other such questions.

Here's a brief guide to helping you choose the right car.

1: The Budget.

Firstly, set yourself a budget, but be flexible. Refusing to be a little flexible leaves little room for negotiation, plus who would want to miss out on their perfect car if it happened to be some £200 out of budget? Obviously be sensible - Only go about 25% above your original upper limit - If you go much more, you may be spending more than you need to. Don't forget to factor in other costs, such as running costs, ie. fuel prices, tax and insurance.


2: Selection

Secondly, do some research. A fair bit of it too - it will help you to establish what car you want, as well as whether it's financially viable long term to want it. The key questions are as follows:

  • What do I want the car for?
  • How long do I want the car for?
  • What do I want the car to be able to do?
  • What manufacturers can offer me these things?


After developing a short-list based on the above question, it's then a good idea to ask a few more...


  • How reliable is the car?
  • What are the potential repair costs going to be?
  • Are parts easy to source?
  • What's the insurance going to be like?
  • Are there any common faults/trends with this car?
  • What condition can I get one of these cars for the budget I've set?


As you can appreciate, the answers the the questions posted above will vary. I know many people who've had great experiences with a particular car manufacturer, and they differ from my own, so it's good to get a fair few opinions before leaning towards anyone or writing anyone off.

Once you've sorted the wheat from the chaff and got answers to the most pressing questions, it's time to make some phone-calls.


3: Arranging To See The Car

Now you've got a short-list of potentials, it's time to visit a few. To help whittle them down even further, put your selections head to head against each other to see if any of them lag noticeably behind the competition. This may give you one or two less cars to phone about. Also, beware of mobile phone numbers in advertisements - If you should be dissatisfied with the car having purchased it, it's very easy for them to ditch that number and get a new one, making them difficult to trace.

It's also best to arrange to see the car in good daylight on a dry day and at the seller's home - This helps make it easier to spot damage. Also check if they're the registered keeper, and check their details (ie. address) on the V5C. It's entirely possible they may be using someone else's home as a backdrop, and not actually be living there at all, so this is important. It's good to ask if the vehicle has ever been in an accident, written off previously or whether it has any outstanding finance - If it does, by buying the car, you'd be buying the debt as well, making you liable.

If you ask the right questions, you'll find you can squeeze a good amount of information out of one phone call.

Here are a few good ones:

How many miles are on the clock?
you might be wondering why you'd bother asking, considering the advert probably tells you... Well that's exactly why you're asking. If the number they throw at you differs noticeably, be aware. If it varies considerably, I would be incline to walk away.

What did you think of the car?
This question doesn't really apply to dealerships - more private sales. It's a good question to ask nearer the end of the conversation as you and the seller will have hopefully developed enough of a rapport for him to be more relaxed and honest with you. If dropped in subtly, they'll be caught off-guard and won't have time to mentally prepare an answer that will cover their backs from every angle, exposing a potential problem or weakness with the car.

What's your reason for selling?
This is an interesting one. Obviously if they're trying to sell it, they're going to talk it up and tell you how fantastic it is. It being so brilliant, you'd expect them to want to keep it, so why aren't they? There are of course a multitude of answers to this, and there are different ways to look at them. If they say they've just bought a new one, or it belonged to a deceased relative, then the chances are they'd be looking for a quick sale, and would be more flexible than some in terms of negotiation. If the seller says the car is a little thirsty, then this is also scope for negotiation, as they would have just bought or be looking to buy a new one.

Are you the original owner?
If the answer is yes, this is ideal, depending on service history and what kind of person you believe the seller is. If they look as though they might like to drive enthusiastically, then this may not be so good, because the car will have been subject to this treatment for most/all of it's life. If it's a woman, the odds are that it's been driven sensibly. In most instances, if the car has had a lady owner since new, or had only one lady owner previously, then it'll probably be in good order.

Has it got a full service history?
This is a good one - this allows you to see whether the car has been regularly and thoroughly maintained through it's life.

Where did you buy it?
Not the most important question, but still a good one - cars sold on forecourts have to meet the criteria set out in CPR (Consumer Protection Regulations Act 2008) and SoGA (Sale of Goods Act 1979), and are therefore a safer buy, but they are more expensive. As such, if someone bought it from a forecourt at an elevated price, there's a good chance they'll pass this extra expenditure onto you, but you wouldn't have quite the same protection in a private sale, making that extra outlay a bit pointless. There isn't a lot you can do about their answer, but it is a factor to be considered.

It's never a bad idea to take a vehicle inspector with you to any viewing. The only downside to it would be cost. Critically, the VIN numbers in the windscreen, on the engine and on the chassis (usually under the bonnet) should all match up, and if they don't, a good solid explanation should be there to explain it. This helps to determine whether parts have been swapped round or whether the vehicle is the one it says it is in the V5C

Once you're happy, avoid paying in cash - You've got less to fall back on if anything should go wrong.

Hopefully this little guide will offer some insight into the world of buying used. I bought my car used and I love it! There were of course a couple of things I wish I'd checked, but all said and done now - It's working well and has done for a good while now, and I hope it continues to do so.

Resources
http://www.oft.gov.uk/shared_oft/reports/676408/oft1242.pdf
http://www.direct.gov.uk/en/Motoring/BuyingAndSellingAVehicle/AdviceOnBuyingAndSellingAVehicle/DG_4022402
http://www.autotrader.co.uk/advice/2010/09/buying/buying-a-used-car

Saturday, 21 January 2012

How To: Understand Computer RAM

There comes a time in everyone's life when they need to know about those three little letters...

... RAM.

1: What The Hell Is RAM?

RAM is short for 'Random-Access Memory'. This basically means it is a small area of temporary storage that the computer can access and utilise in order to run programs.

You see this webpage? Your computer is using RAM right now in order to temporarily store the information displayed here for you to see it and read it. When you go to a different page, this information is overwritten by the new page, and this continues...

Say you get bored browsing the web and you feel like watching a film, so you minimize the window and open Windows Media Player or something. When you load WMP (Windows Media Player), the information needed to run the program, generate what you see and hear etc. is all loaded from the hard drive into the RAM while you're using it. The web page you were looking at earlier is still in the RAM, waiting to be used or closed.

2: What different types of RAM are there?

Well, in short, there are many. SD, RDRAM, DDR, DDR2, DDR3, SIMM, DIMM and SODIMM. I'll try and break them down into more familiar sections...

2a: Desktop Computer Memory.

I could go on about the history of RAM, but it's not constructive. What we need to know is what today's RAM (2012) is about. The current most common formats are DDR2 and DDR3, and out of those, DDR2 is older and being phased out in favour of DDR3, which is faster. Firstly, the terminology; DIMM is short for 'Dual In-line Memory Module', while DDR is short for 'Double Data Rate'

DDR2 DIMM and DDR3 DIMM are distinguishable thanks to the location of their 'notches'. There are small cut-outs in the RAM stick that mean it can only fit into one type of slot. This is to help avoid confusion in the fitting process. If it doesn't fit, it's not meant to.

DDR2 has a notch cut out broadly in the middle. It's not exactly in the middle, but it's near the middle. DDR3 RAM has a notch cut out nearer one side - which side of course depends which way up you're holding it!




File:Desktop DDR Memory Comparison.svg

The above shows DDR2 and DDR3 RAM for a desktop PC. Notice on DDR2 the notch is near central, while on DDR3, the notch is more towards one side, in this instance, more leftward.



The speed of RAM is critical. This number tells you how much data can be moved in and out of the RAM simultaneously. This is measured in a unit called MT/s, which is short for 'million transfers per second'.

Typically, DDR2 is available at the following speeds; 400, 533, 666, 800 and 1066.

The higher the number, generally the better, as it means improved data transfer rate. What's absolutely critical is if you plan to have more than one, say you've got 2GB in your PC but you want to make it 4GB, it's vital that this number is checked on each stick of RAM to make sure this number matches. If they don't, you're going to experience problems.

DDR3 is available in the following speeds: 800, 1066, 1333, 1600, 1866 and 2133.

Same principle applies with DDR3 as it does for DDR2 - The speeds NEED to match if you plan on having more than one stick of RAM.

The other numbers on RAM are not generally important for day-to-day computer fixing/upgrading tasks. However, if you need to know them, see 'Advanced Stuff' section within each topic.

2b: Laptop Computer Memory

Laptop memory, known as SODIMM (Small Outline Dual In-line Memory Module), is largely the same in terms of principal as ordinary DIMM memory. The only thing that differs significantly is the size and shape of the sticks, as well as the position of the notches.

DDR2 SODIMM laptop memory has it's notch closer to one side, making it difficult to distinguish from DDR SODIMM. However, DDR3 has it's notch closer to the middle. It's not totally central, but it's moreso than it's DDR2 counterpart.


Notice with SODIMM, the modules are smaller, designed specifically for smaller devices/computers. Also notice that DDR and DDR2 are very similar in shape, with only 1mm separating their notches. Be aware of this when identifying RAM!


 ADVANCED STUFF: There's a number present on some RAM called CAS latency. This is measured in 4 numbers separated with a hyphen ie. 5-5-5-16. Without getting too advanced, these numbers measure the time it takes for the information on the RAM to be accessed from the moment it is told to access it. The lower the numbers, the better, but considering this time lapse is measured in nanoseconds, the average user is not really going to notice the difference/feel the full benefit of this.

So there we are. Hopefully this little, brief, uncomplicated guide to RAM will help you select the right one, identify RAM you already have, and determine if they are compatible together.