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Four-wheel drive versus all-wheel drive. Easy Select versus Super Select II. What does it all mean? If my inbox is anything to go by, there’s great uncertainty out there about all-wheel drive and four-wheel drive. In reality, it’s not that simple. Or at least, not clear-cut. Let’s clear a few things up: Firstly, four-wheel drive. Let’s define that, arbitrarily, as a system designed only for low traction surfaces, slippery underfoot, in which the drive to the front axles and the drive to the rear axles can be locked together at the same rotational speed, using Fred Flintstone engineering. In other words, the front and rear prop shafts are mechanically locked to rotate at the same rate. All-wheel drive: Let’s define that arbitrarily as a system designed to drive all four wheels, either continuously or occasionally, but with the front and rear prop shafts able to turn at different rates. And that means you can use all-wheel drive on high-traction surfaces (like sealed roads; dry bitumen). The big difference: When a vehicle drives on a curve, the front end and the rear end follow different paths. Therefore, the front and rear ends travel different distances. Therefore, on a high-traction surface, the front and rear prop shafts need to spin at slightly different rates. On a low-traction surface, the tyres can slip a bit, if the front and rear prop shafts are locked. But if you put a vehicle into four-wheel drive mode (prop shafts locked in unison) and you drive on a high-traction surface, on a curve, you will break something - at least, you open this door, and warranty will not cover you because that’s technically abuse. So - all-wheel drive vehicles have some sort of sophisticated coupling between the front and rear prop shafts - either a differential, or a viscous coupling, etc, that allows this relative rotation. They’re more sophisticated, and therefore, more expensive. Most all-wheel drive SUVs have a four-wheel drive mode, usually engaged with a ‘lock’ or ‘4WD lock’ button, or sometimes a rotating switch. Typically you engage that to get through some mud or soft sand - whatever. In the snow. But not for driving on bitumen - if you know what’s good for you. I’m John Cadogan. I hope this helps. Thanks for watching.
Oil Consumption in Modern Cars: The Truth Does your car have a drinking problem? A destructive relationship with engine oil? Is the manufacturer brushing you off as it churns and burns oil between services? Plenty of people complain to me about this. Here are the facts. Now look - there’s nothing I like more than the repetitive application of lubricant. Maintenance is very important. Frankly I get several hundred complaints by e-mail about alleged excessive oil consumption. Often in relation to Audi, Holden Colorado, and Subaru. Luke’s question on this is typical - I’m just picking his because it’s the most recent. And he’s literate - he uses sentences and everything, which is not always the case. “I have a 2014 Holden Colorado with 67,000km on the clock. I’ve owned it since new and it is using two litres of oil between 15,000km services. Car has been fully serviced. Holden has replaced the dipstick and continued to monitor it for a year and have now put 5W40 in it at the last service but it hasn’t helped. I have recently been told in writing by my local Holden dealer that “Anything below 2.5l per 10,000km is considered acceptable, and additional top ups between services are not uncommon. Is this reasonable?” To do this question justice we need to do a crash course in engine design basics - past versus present: In the past, engines were built tight, and they consumed, essentially, no oil for years (if you maintained them). Then, inevitably, wear would overcome them, and the piston rings and/or valve guides would give up the ghost. After 150,000 kilometres, or whatever, mechanical wear would take over, blow out the clearances, and as a consequence, a great deal of engine oil would burn, and every takeoff at the lights would make you look like the Batmobile in ‘smokescreen’ mode. Wear would then accelerate and your engine would be a dead man walking. Then, about a decade ago, maybe 15 years, manufacturers started to get real serious about fuel consumption, and there are three ways to tackle that. The easiest way is just to make cars lighter - but since that also makes them, typically, smaller, and less brimming with the cool toys you expect, manufacturers are disinclined to do that. Cars keep getting bigger and heavier. The second way is to improve combustion efficiency - which is what variable valve timing, direct injection, variable geometry turbos, etc. - all the cool engine engineering toys - are about. Burning the same amount of fuel and extracting more useful work from it. And the last way - in many ways the most accessible way to make real efficiency gains - is to tackle resistance. Things like aerodynamics, rolling resistance, and internal friction. Losses. These are the things you can’t feel, but which your engine needs to battle every rev, just to get your car out of the blocks and moving. Internal friction in your engine is one of those big-ticket ‘losses’ items. So, in an effort to reduce fuel consumption, manufacturers have for several years now waged war on internal friction in engines, and they’ve wound back the tension in the piston rings and valve guides, in particular. This saves fuel (and it saves you money - let’s not forget that while you’re bitching about oil consumption - you’re saving money on fuel here) but it also opens the door to oil consumption. And this understandably sets off warning bells in some owners’ minds at least. This oil consumption is a feedback effect - looser piston rings and valve guides slide easier but allow some oil to be burnt. Classic example of an overall positive change also generating negative feedback.
How much fuel does engine idling use? Does idling waste fuel? How much fuel does it take to start a car? Do engine start-stop systems save gas? The truth about engine start stop systems. EE Shirts! - http://bit.ly/2BHsiuo Recommended Books & Car Products - http://amzn.to/2BrekJm Subscribe for new videos every Wednesday! - https://goo.gl/VZstk7 How much fuel does an idling engine use? After how long will an idling engine use more fuel than simply shutting the engine off, and then restarting it? It turns out, most Americans have no idea, as the journal of Energy Policy interviewed 1,300 US drivers, and the average time guessed was 3.6 minutes! 3.6 minutes worth of engine idling fuel required to simply start up an engine! Well, let's put the myths to rest and look at actual data, published in the journal of SAE. Researchers took two identical engines and measured their idle fuel consumption, how much fuel they required to start up, and then spent time conducting real world driving tests to see if engine start-stop systems actually save fuel. Check out the video to see the results! Reference Material: SAE Idle Stop Fuel Consumption - https://bit.ly/2PzNRzZ Energy Policy Study - https://bit.ly/2wGkrcp Engineering Explained is a participant in the Amazon Influencer Program. Don't forget to check out my other pages below! Facebook: http://www.facebook.com/engineeringexplained Official Website: http://www.howdoesacarwork.com Twitter: http://www.twitter.com/jasonfenske13 Instagram: http://www.instagram.com/engineeringexplained Car Throttle: https://www.carthrottle.com/user/engineeringexplained Amazon: https://www.amazon.com/shop/engineeringexplained EE Extra: https://www.youtube.com/channel/UCsrY4q8xGPJQbQ8HPQZn6iA NEW VIDEO EVERY WEDNESDAY!
How to Buy a Car: Top 6 Tips to Buy New Cars details the top six things new car buyers don’t investigate, but should: NEW CARS: BUILD DATE A listener of mine on Radio 2UE in Sydney put a deposit down to buy a new car in January 2015. It turns out the new car - a Suzuki S-Cross - was actually built in 2013. The compliance plate went on in 2014, and the new car was set for delivery in 2015. Disaster. Get a discount on your next new car if you’re actually buying old stock - last year’s model - because you are certainly going to pay for it at trade-in time. NEW CARS: SPARE TYRE When you buy a car, check the spare tyre. Space saver spare tyres are one of the car industry’s great, enduring frauds. They are of absolutely no benefit to you on a new car. They’re limited to 80km/h, and they don’t grip the road very well. Always investigate your intended new car’s spare tyre, at the dealership, before paying a deposit - and sometimes you can negotiate to fit a full-sized spare when you buy the new car. If it’s critical to the new car sale, the car dealer might even throw it in for free. If you only ever drive 15 or 20km from home in suburbia, space-savers are probably OK. But if you get out on the highway, even occasionally, don’t risk your life by buying a car with a space-saver. They’re a joke. NEW CARS: LIGHTS You don’t normally test drive new cars at night, right? But there are two things you really should check here: outside the new car, you need to know whether the headlights - and in particular the high beams - are adequate. Some new cars are just anorexic in the high beam department. Again, not so important if you only ever drive in the city, or suburbia. But very important in the country. Inside the new car, the reverse applies. Dimmers on instruments are great for driving in isolated areas at night - you dim the instrument lights down to maximise night vision out there on the road ahead. Very important. But the big, fat centre LCD display often doesn’t dim sufficiently (or at all) for night driving. NEW CARS: DEPRECIATION There are two ways to lose money on a car. You can pay too much for it up front, or the depreciation can burn you at the back end of the deal. OK - all cars depreciate, but some depreciate like Dresden on the ides of February, 1945. A classic example here was in last month’s Ford Territory review - which Ford fans hated, principally because it’s such a lemon. Mechanically as well as on the depreciation front. It pays to do your homework on depreciation - and here, past performances are excellent indicators of the future. NEW CARS: UPDATE TIMING You don't want to buy a nice new whatever, and see the manufacturer upgrade it four weeks later. Even a mid-life upgrade is a bit of a disaster because a) it usually comes with more standard equipment at the same price and b) the one you bought - the suddenly ‘old’ model - becomes instantly obsolete and its value takes an immediate hit. You need to let your keyboard do the walking here: google the car you want and keywords like update, upgrade, plus the current year and the next year. Find out what’s going on in the near future. NEW CARS: FIRE SALES Here's what the car industry does with its marketplace dogs. When all else fails, and sales have flatlined, the manufacturer bends over and drops its pants. Every time. They fire-sale the price in an attempt to prop up or stimulate sales. Generally unsuccessfully. Holden dropped its pants on the latest Cruze and Commodore, and Ford has just played the same undignified card with the Territory. Although none of them put it like that in the press releases... So I guess that's good news if you desperately want a Cruze, a Commodore or a Territory… Of course, if you actually bought one of these marketplace lemons a few months earlier, guess what happens to the value of your car? It just evaporates. Desperation discounting by manufacturers slashes the same amount from the value of the lemon you own - because used car prices vary directly in line with replacement cost. So there you go: Six things you probably weren’t considering while you’re poring over the specs and the pretty pix of your possible next new vehicle.
The acid-dropping, crack-smoking, marijuana cookie-chomping, self-administering recreational pharmacologists at Ford … well, they’ve done it again. In public. And this time they are literally yanking your chain. Full report: http://autoexpert.com.au/buying-a-car/ford-ranger-centrifuge-commercial One of the most technically nauseating, yet visually compelling, but critically flawed, ads you will ever see is the Ranger-centrifuge, or so-called ‘Rangerfuge’ [TILT] episode of Ford’s ‘Science or Truck’ advertising campaign. Let’s take a look. I’m John Cadogan - the Chief Inquisitor of scientific heresy here at AutoExpert.com.au - the place where even sir Isaac Newton would have saved thousands on his next new car - if only the automobile have been invented in the 17th Century. Hit me up on the website for that - even if you’re not a dead scientific genius. This dreadful embarrassment dressed superficially as science occurred when Ford decided to affix both of Iron Mike Tyson’s 300-kilo steel grey gonads to a Ranger rig mounted, creatively, on a Nutribullet. The Nutribullet is set to ‘puree’, and Iron Mike’s twirling black nuts are in a 4.7-G tensile teste-tugging twist. It’s a novel way to proof load a chassis. They call it science, but what did it prove? Stuffed if I know. It proves the facts don’t matter as long as this visuals are compelling. It proves Ford thinks Ranger buyers are somewhat retarded. It proves no technically literate people were detained in the production of this commercial. It proves you could do it a whole lot better. This ad is in fact a travesty of scientific misrepresentation. Which is a real pity because it purports to be science, and we need better scientific literacy and more mainstream interest in science. We’ve never needed that more than we do right now. So here it comes: the blow-by-blow on this commercial’s exhaustive science snafus. 96 seconds of unforgiveable misrepresentation. Let’s tally up these venial science sins.
One of the most glaring examples of this carmaker agenda self-serving design is the auto engine shutdown and restart system.
You drive along. Stop at a red light. The engine automatically shuts down. Light goes green, you start lifting off the brake, and the engine kicks back into life, as if by magic. We’re talking about that.
Systems like Mazda’s iStop - and seemingly 100 other proprietary names for similar bullshit technology. I get questions about this all the time.
So here it is: The truth about bullshit auto engine shutdown and restart systems.
Number one with a bullet: they save you bugger-all fuel. Claims that you will save any appreciable money are unmitigated bullshit. You can idle your engine all day long, and it’s still not going to cost you as much as a burger and fries. Engines just don’t consume much fuel at idle - they’re really only driving the ancillaries, overcoming their own internal friction and a bit of drag in the torque converter (if they’re driving an automatic).
The real reason these automated systems exist in many new cars is so the carmaker can legally ‘game’ the official fuel consumption tests. We’ve discussed these tests before. They’re lab tests from which the official fuel figures are derived - and these numbers are very important to carmakers, because consumption is increasingly important to buyers.
Unfortunately the tests are not very representative of actual driving. They’re just not - the official test numbers are always better than you can achieve out there, on the road, and that leads to a lot of customer dissatisfaction. Unfortunately.
The most non-representative aspect of the tests is the amount of time the cars spend stopped in both the city and highway tests. Those valleys there? The car is stopped. Together, both tests take 20 minutes - and around one-third of that time is spent stopped. In the city cycle test - it’s almost half the total time stopped.
So if you’re a carmaker, and you’re in this intense competition with all other carmakers, and you include the engine shutdown feature in the car, almost half of the official city cycle test is spent with the engine shut down. You’ll make incremental gains over a competitor without that system in his car. So, congratulations - you just gamed the system, and there’s nothing illegal about it.
But what this means for you, the car owner is: you have to wear it. And it’s unpleasant - especially on restart. Especially in a diesel, which has to battle a lot of compression when it restarts. And especially if your car has a CVT transmission. They tend to have pretty aggressive torque converters. So the restart is unrefined, at best. It’s awful.