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ALLOY WHEELS:
What is an alloy wheel?
Until recently, the wheels fitted by most manufacturers to their every-day cars have been "steel wheels" Steel wheels are more resilient to damage, and are considerably cheaper to fit. Unfortunately they are almost always heavier, less attractive and smaller in both diameter and width than alloy wheels.
The term alloy wheels is usually given to wheels 'cast' from a mixture of aluminum which is light weight and great at dissipating heat and small amounts of more rigid metals whose presence in the 'mix' provides rigidity and helps prevent cracks propagating.
What are the benefits of fitting Alloy Wheels to my car? 
In general, alloy wheels are lighter, more attractive, and better at dissipating brake heat that their steel counterparts. They tend to be available in standardised sizes which means competition amongst tyre vendors giving low prices and good availability!
Fitting alloy wheels normally reduces your car's unsprung weight - in layman's terms this means a reduction in rotating mass at the ends of your suspension components, giving you improved steering feel and greater braking response.
Offset is the distance between the hub mounting face at the back of the wheel and the wheel's centreline.
Offset is usually stamped or engraved into the wheel and is measured in millimetres of 'ET' [ET is the short form of the German word 'Einpresstiefe' which literally translates as 'insertion depth']
Positive Offset wheels have their mounting face toward the front face of the wheel. Most front wheel drive vehicles have positive ET wheels. Eighties and Nineties Volkswagen wheels are usually ET38.
Zero Offset wheels have their mounting face even with the centerline of the wheel and are by definition "ET 0".
Negative Offset wheels have their mounting face toward the rear of the wheel - powerful rear-wheel drive cars often have wheels with negative offset.
What does PCD mean?
PCD stands for 'pitch circle diametre' and is the diametre of a circle drawn through the centre of your wheel's bolt holes. P.C.D. is measured in millimeters and also indicates the number of studs or bolts the wheel will have. Volkswagen Alloy Wheels are usually either 4x100 [i.e. 4 bolt holes drilled through the centre of an imaginary 100mm circle] or 5x100 [VR6s, GTis and MK4s]
What does Centrebore mean?
The 'centerbore' of an alloy wheel is the size of the hole at the back of the wheel which the 'hub' fits into. To help the wheels to seat properly this hole needs to be an exact match to the size of the hub.
Most modern wheels are what's called 'hub-centric' - this means that the hub which protrudes from your car [and mates with the equivalent sized hole at the back of your wheel] is 'load bearing'. All the studs or bolts do therefore is hold the wheel onto the hub!
If you have' lug-centric' wheels, the state of your studs or bolts is obviously more critical - be sure to replace these from time to time and always 3/4 tighten the wheels off the car to ensure they're centred.
What does Plus-Sizing or Up-Stepping mean?
Plus-Sizing or Up-Stepping are two terms given to the practice of increasing the diameter of your wheels whilst simultaneously reducing the profile of your tyres to keep the overall rolling radius the same.
Benefits - Plus-Sizing will improve the handling of your car! - each step will reduce the proportion of flexible tyre 'sidewall' to rigid alloy. This will improve response, will help keep the tyre tread square to the road and will improve your car's 'feedback'. If done properly speedo and odometer accuracy will be retained and the car's sure to look better..
Disadvantages - In the majority of situations, tyre inches are lighter than wheel inches. Plus-sizing can make your overall wheel/tyre package heavier. Reducing the profile of your tyres will also reduce your car's damping deflection under compression [the ride quality will get worse] Other disadvantages can include you needing more expensive tyres, your brakes looking puny and people's grannies laughing and calling your car a pram.
Before you do anything, check to see that you the right sort of bolts - B olts and studs have various diameters, threads and seatings, your wheel supplier should be able to advise on this. Also check to see that you the 4 plastic spigot rings which help the interface between the wheel and the hub.
Next you need to jack your car up - do this securely and be sure to use axle stands, chock wheels still in contact with the ground and apply the parking brake. Offer a wheel up to the car and check that the bolt holes line up, that the wheel locates on the hub correctly and that there is wheel arch, suspension strut and brake caliper clearance [if you have upgraded your brakes be SURE to seek advice and measure everything thoroughly BEFORE you order!].
Alloy Wheel Care
As anybody who's stepped into a motor factors in the last 10 years will tell you, there's a huge variety of specialist wheel cleaners on the market, all designed to help make the job of cleaning your new rims that little bit easier, unfortunately the real key to a great finish is hard work.
Before you fit your wheels, give them several coats of good quality car polish back and front. This will help prevent the road salt, brake dust and dirt 'keying' to the surface on first use. Be sure to treat the surface of your alloys as well, if not better, than you would your paintwork. Remember, you've spent a small fortune of your alloys and they're going to be subject to the harshest conditions of just about any part of the car!
Frequent washing with mildly soapy warm water [having hosed all the loose abrasive grit off first] is the best way to keep wheels clean. Never use abrasive cleansers, electric buffers or wire wool pads on your wheels. Where possible let your wheels cool thoroughly before cleaning them and avoid car-wash wheel-cleaners at all times.
Smart Fortwo Pulse mhd
People buy Smarts because they're extreme. The shortest, the easiest to park, the most evidently urbanized car of our times. Trouble is, a Smart isn't the most ecological any more, and Smart's target 'reduce-to-the-max' urbanites want it to be.
So, here's the mhd version. It cuts the CO2 figure from 112g/km to 103, squeezing it below the Prius and Mini Cooper D.
Though Smart is leading with the chin and using the H-word - mhd stands for micro hybrid drive - it isn't what you and I know as a hybrid. It can't proceed under electrical power. It doesn't recover any energy on the over-run, nor boost its acceleration electrically.
In fact, the degree of trickery is less than the stop-start system now standard on Minis or low-end BMWs.
But let's not carp. The mhd option, when it comes to the UK next year, will only add about five per cent to the price of the car and yet allows a Smart to go about eight per cent further on a litre of petrol. If you're confined to driving in towns, the savings would be proportionally greater.
It's basically a stop-start system. You come up to a red light or clogged junction. Just as you roll down to walking speed, at the same time as the automatic clutch disengages the engine cuts out.
Sit foot on the brake and you're in silence, bar the radio and ventilation fans. Lift off the brake and the engine starts, so that by the time your foot has shifted to the accelerator the engine's ready for you. Provided you're not the sort of person who left-foot brakes (in a Smart? Why ever would you?) it all works entirely without a hitch.
The normal starter and alternator is replaced by a single big-capacity belt-drive starter/generator, which is simple in theory, but a bit complex and expensive in detail.
If the engine isn't warm enough or the battery not charged enough, the engine doesn't cut. And you can inhibit the system with a centre console button, though I can't see why you would.
Let's face it, a Smart three-cylinder isn't the world's most unobtrusive engine at idle, and it's really rather pleasant to be freed from its chuntering vibrations.
In all other respects it's the same as the regular Smart. Fine by me
Fiat Bravo 1.4 Dynamic T-Jet 150
Start small, get bigger and Fiats get steadily worse. Let's have a fun look at the Fiat sliding scale from excellence to plop, shall we? Panda and 500? Class leaders and world beaters, characterful little machines full of sparkle and brio.
Punto? Well, not quite as brilliant, but still proper Fiat fare; nippy, cute, quick and instantly recognisable, a refreshing Latin antidote to the anodyne Polo or anything Japanese of a similar size.
Then we get to the car on this page, the new Bravo. We like it, quite a lot in fact, but it's slipping into slight mediocrity, holding on to some of the Punto's style and energy, but falling behind its rivals in other important ways.
Things are tough in this class, hideously tough, whether it's the value end of the market with kit like the Kia Cee'd and Hyundai i30, in the centre with Focus and Astra, or higher up with the Volkswagen Golf and Audi A3.
The Bravo is keenly priced, falling somewhere between Cee'd and Focus. It doesn't quite beat the Ford, but it destroys anything cheaper because it has proper character. And it's way, way better than whatever the larger Fiat is called. Er, I've forgotten. Cryo, Cromey, thing.
The new Bravo deserves to sell well on its styling alone. You'd have to be a pretty harsh critic to call it ugly. Park it next to its rivals and there's no mistaking its sleek, Maserati-esque nose with its elongated headlights and bold grille - more than you can say for the Focus/Golf/Auris/Cee'd circus, which are playing it way too safe.
The tail is neat and fuss-free, too. There's always demand for Italian flair and that's why Fiat is making such a tidy profit these days.
Hop into the Bravo and you're greeted by a fresh, bright interior with plenty of contrasting textures and materials. High quality it's not, sadly, but at least it's different to the standard German, bland, black/grey fare.
The dash has an organic sweep, with a driver-focused upper console and classic Italian-style embedded dials.
It's not comfortable behind the wheel if you're tall. The driving position compresses your legs - a result, it seems, of pedals that are too far from the floor. Your ankles and knees flex severely and there's no foot rest. Not good.
Still, the car rides well, points well and goes very well, especially this T-Jet 150, a 1.4-litre turbo with 150bhp. All of the engines are excellent, but the Bravo is too unrefined and unfinished to mix it with the best in this class. Maybe it's just too big to be a great Fiat.
Invention of the Diesel Engine
Posted On Sunday, September 9, 2007 at at 6:49 AM by Sanky
In 1898, Rudolf Diesel was granted patent #608,845 for an "internal combustion engine" the Diesel engine.
The diesel engines of today are refined and improved versions of Rudolf Diesel's original concept. They are often used in submarines, ships, locomotives, and large trucks and in electric generating plants.
Though best known for his invention of the pressure-ignited heat engine that bears his name, Rudolf Diesel was also a well-respected thermal engineer and a social theorist. Rudolf Diesel's inventions have three points in common: They relate to heat transference by natural physical processes or laws; they involve markedly creative mechanical design; and they were initially motivated by the inventor's concept of sociological needs. Rudolf Diesel originally conceived the diesel engine to enable independent craftsmen and artisans to compete with large industry.
At Augsburg, on August 10, 1893, Rudolf Diesel's prime model, a single 10-foot iron cylinder with a flywheel at its base, ran on its own power for the first time. Rudolf Diesel spent two more years making improvements and in 1896 demonstrated another model with the theoretical efficiency of 75 percent, in contrast to the ten percent efficiency of the steam engine. By 1898, Rudolf Diesel was a millionaire. His engines were used to power pipelines, electric and water plants, automobiles and trucks, and marine craft, and soon after were used in mines, oil fields, factories, and transoceanic shipping.
Rolls Royce Phantom & Jaguar
Posted On Saturday, September 1, 2007 at at 10:45 PM by Sanky
Other cars, including the Z4M Coupe long termer I went to collect the Phantom in, just look like bits of discarded tin. There's a solidity and menace to the Rolls which is lacking from others.
Which means that my route to work this morning wasn't as relaxed as it should have been. Even allowing for the terrible traffic that was meant to be better with the congestion charge. Because there's a width restrictor on my way.
I don't have to go that way. There are two other routes, but both were pretty clogged up. I'd said before I left home that I wouldn't go through the width restrictor. I'd promised myself that. Too much hassle, and I doubt my annual salary covers any kerbing to the 21-inch alloys.
But then the traffic loomed. So I went for it. Then bottled it. There is a wider route if you go the wrong side of this width restrictor, and there wasn't any traffic coming through it. Quick, reverse.
Damn, someone's behind me. And someone else is waiting to turn into this concrete tank trap as well. So it's just edge and go.
The Phantom might be more focused on the driver than the Maybach, but that doesn't make it easy to slot through here.
Kill the radio, keep the wheels straight and just pray. Breathe in, because I find that always helps. I didn't dare look in the mirrors, or use any of the cameras at the front and back. So I've no idea how close I came to the kerb.
Until now. I've just worked out that I had seven centimetres either side. Look at that on a ruler - makes the Phantom seem even bigger.
A new look for the big cat
Unofficially, the team behind the XF called it “the new Mk2”, both to differentiate it from the S-type and XJ, and to associate it with the charisma, the compact shape and the fine driving qualities of that enduring '60s icon.
This new rival to the Mercedes E-class, Audi A6 and BMW 5-series certainly doesn't need a collection of outmoded styling cues. After the failure of successive retro designs, Jaguar, under the guidance of design director Ian Callum, has found a new look.
The XF ditches both the “shield” grille of the old Mk2 and recent S-type saloons, and the “mouth” grille of the XK. Instead, it uses a new “ovoid” shape, related (albeit faintly) to the grille of the first XJ6.
Its stance is low-nosed and confident, full of latent power, with the grille countersunk into the body in the manner of the original XJ, not merely stuck on.
In the cabin
The interior is a confection of simple planes, graceful lines and quality materials. But lest anyone think traditions are being chucked overboard, Jaguar designers point out that the the XF cabin nevertheless contains more wood than any Jaguar since the Mk2.
Front occupants sit low, separated by a high centre console to give the familiar Jaguar feeling that you’ve located securely in a “tub” of your own.
Get into the car, close the driver’s door and the “start” button located on the console pulses red. Press it, and two things happen. The engine starts, and a rotary knob rises out of what you thought was the flat upper surface of the centre console, to become a rotary gear selector knob.
It looks and moves like the polished alloy knob of a piece of top-quality audio equipment, because the driver’s control of the specially tuned six-speed ZF transmission is ‘by wire”. Every XF also has paddle-shift control of the 'box. There is no conventional manual.
Under the skin
Four engines are offered – a 2.7-litre, 210bhp turbodiesel V6; a 3.0-litre 240bhp petrol V6, a 4.2-litre, 300bhp petrol V8 and a 4.2-litre, 420bhp supercharged V8.
The slowest top speed is 143mph in the diesel, and the slowest 0-60 is 7.9 seconds in the 3.0-litre V6. At the other end of the spectrum the SV8 rockets from 0-60mph in 5.1sec to a limited 155mph top speed.
Unlike the latest XK and XJ, the XF doesn't have an integral body/chassis in aluminium. Instead, it uses high-strength steels, plus a wide variety of materials including aluminium, composites, plastics and magnesium alloy.
The XF shares its 2909mm wheelbase with the outgoing S-type, and the same goes for its coil-sprung, double wishbone front suspension and multi-link rear, both mounted on subframes for the best possible isolation.
All but the supercharged SV8 model have ventilated 326mm disc brakes all round, but the top model has 355mm units on the front for extra retardation. It needs them not only because it is so fast, but also as its claimed kerb weight of 1842kg is 160kg above that of the lightest model, the 3.0 litre petrol V6. The 2.7 litre turbodiesel (1771kg) and normally aspirated 4.2 V8 (1749kg) fall in between.
The XF’s most important unseen component is likely to be the sophistication of its ride and handling development, carried out by a team led by Mike Cross. We look forward to finding out.
