Today while I was filling up my 2003 Corolla with gas, a guy drove up to the next pump in his 1952 MG convertible. Which gets 30MPG. My Corolla gets 27MPG.

Erm, you realize this is talking specifically about engine micro-controllers right?

-40F is equal to -40C

Your GPS unit is not an "automotive cpu"... It is a consumer product fitted into a car.

The automative processor is what controls your fuel injection, ABS and other such functions.

There is a world of difference between the two.

Metro's 90-04 were about the same. The block containing the electronic controls for the engine would actually corrode from the inside out. Things with automotive electronics only started to get "good" around 94 when GM first kicked out the 3800 series that was fully electronic controlled, and everyone and their grandmother saw "it was a good design" and copied the piss out of it.

By around '96 things were leaps and bounds ahead of where they were even 2 years before that.

Agreed, it's not revolutionary - but each generation is a nice improvement.

The tech is new but the design is biased towards factors other than outright performance (obviously). If you consider microcontrollers like the very popular Atmel AVR32 series, they're barely pushing the speed but their technology is very current. Things like integrated ADC/DAC/SPI/TWI~I2C/USARTS/USB/CAN/opamps/comparators/counters~timers/safety-circuits/power-savings (down to nA range) are what's important. The modern microcontroller is an amazing toolkit of modules, vastly reducing your board build complexity and improving your longevity.

  Looking at the highres photo of the board, you can see it's mostly just a hell of a lot of power regulators, switchmode-controllers and MOSFETS (for the switchmode power) with a couple of ASICs. There's also a lot of safety bits on there such as polyfuses. My first impression of this design is that there's a lot of isolated power channels to ensure that even if one goes down everything else keeps on going.

Yes, It is called the OBDII port.

Other plants can be used to make ethanol, but it's not being done widely

Sure it is. Brazil has been producing efficient sugarcane-based ethanol for decades, and now accounts for almost 40% of the world's ethanol fuel production. Not that it matters much to the US, because of the quotas and massive tariffs to protect the crappy corn ethanol industry...

It probably won't. Most ECU's have a very small RTOS, usually based on OSEK or AUTOSAR standard.

Please do not compare engine ECU processors to GPS interface processors. The GPS units do not have runtime requirements (just like in Windows). The ECUs have to make some calculations at very small reccurence. Missing such a timing can have dezastruous effects. Think about this: and engine at 8000rpm will complete one rotation in 7.5ms. So the better control you have over the injectors and spark plugs, the better fuel efficiency you can get from one burning cycle. While a diesel will probably not reach 8000rpm, just think about this: a fuel injection cycle has 3 stages, pre-injection, injection and post-injection. In the pre- and post-injection the fuel quantity is pretty small compared to the injection phase, but all this is done during half of rotation (maybe a little more, as I don't know about the advance). So at 5000rpm (at which some diesels cut fuel), you have 12ms for one rotation, that means 6ms for making 3 separate injections. And you also have to monitor many sensors to prevent some damages. If you would rely on windows (even CE), you would kill you engine pretty quickly.

And what they are talking about is currnet products (released engine). I can tell you that they are already working on a 133MHz processor which can also run at 180MHz (Infineon Tricore 1782). But projects based on these will probably not see the day in 2011.

Also, if you compare a core2duo, you should be aware that we are talking about less than 1W microcontrollers. Also processors which are rated for 15 year in 125 C ambiental conditions. Your C2D would have tripped the shutdown signal long before your engine was getting warm, as it's around 100C at junction level, not ambiental.

Actually it's the low torque delivery the reason why the trucks use it. A gasoline engine needs high rpm, so on big engines like trucks, you either used low-revs which do not generate good power or high-revs which increased engine wear very much. Diesel just had the compromise.
But on car side, it was power that was needed by consumer, and even today, for the same cylinder volume, you need a turbo-charger for the diesel to get close to the same power comparing a gasoline engine. Only in the last 10 years big developments were made in diesel thanks to embedded microcontrollers.

IME Toyotas handle like dogshit, especially Corollas. Celicas are not too bad but have a tendency towards understeer. Mazdas just feel cheap, but I've never driven an Evo with its strengthened unibody. They skitter around the pavement, and yes, I've been in RX-7s. The Miata is a notable counterexample also, it feels like a Nissan, which is to say almost solid (cage it up) and VERY light and tossable despite weighing as much as a Civic, or an Accord; both feel solid (for their weight) but also feel heavy while turning. And then there's Subaru, by far the most nimble of the bunch, but also the most gutless except in the WRX or better.

That test is silly because nobody drives sports cars for performance without upgrades. They're equipped with low-rolling-resistance tires in stock form for mileage in most cases. Put some real rubber and shocks on those little sports cars and they'll have a shot again (although again, Jags handle like poop compared to their Mercedes and BMW competition.)

If you strip out all the parts of Linux you don't need, you can get it considerably smaller. [ucdot.org] And if you remove the ability to run additional processes, and put your entire program directly into the kernel, remove module support and compile all drivers directly, and so on, you can get it down even smaller than that.

It may not crumple, but it can do terrible things to the driver in an accident. Modern cars are designed to crumple (in a controlled manner) and have a reinforced passenger compartment to keep large pieces of metal from impaling human beings. I'll never find it now but there's a great video online of a big 60s era car in a front end collision with some tiny little "send your kids to college in me" buggy from 2010. Superficially the big car wins, but the "driver" (dummy) is almost certainly dead.

I used to drive an MGB convertible. Great car, I knew it'd kill me in a heartbeat.

As a teenager in northern Canada, I learned that you need to warm up the transmission as well as the engine in extreme cold. A friend of my dad's forgot this lesson and and had to replace his car's automatic transmission.

In extreme cold, you can protect your transmission by putting it in neutral for a few minutes. This gets the transmission oil moving (and warming) without engaging more delicate mechanical parts. Do not leave an automatic transmission in "Park".

BTW - While several minutes of idling in neutral during EXTREME cold conditions are required to warm the transmission, 90 seconds of idling is all your engine needs. Any extra idling time is for only for the driver's comfort (i.e. warms up the cars interior )

Diesel engines do not mix air with fuel at the intake stage, but rather at the tail end of the compression and just before the ignition cycle. Standard EFI gas engines create an air/fuel mixture which is fed into the engine at the intake stage and then compressed. Direct injection of gas engines operate similar to a diesel and are becoming increasingly common as emissions and fuel economy requirements become more stringent however EFI is still dominant.

Diesel/direct injection of gas allows high compression ratios because you don't have to worry about pre-igniting the fuel during the compression stage because at that point you're basically only compressing air and only supplying fuel at the last possible moment to kick the ignition stage.

You're correct - but also wrong.

Diesel is inherently less efficient than Otto (Spark ignition). Refer you to pretty much any actual text on engine thermodynamics. Look closely and see which is closer to the idea Carnot cycle - the Otto cycle is!

If you were to compare the two with an engine of identical compression ratio, at identical load and speed - you would find the spark ignition cycle to use less fuel.

Why are you otherwise correct? Compression ratio.
Apart from the very newest of engines with direct-fuel-injection, spark ignition fuels tend to easily detonate rather than conflagrate at high compression ratios - leading to a release of energy too fast for the engine to harness. ("pinging", which often also leads to a broken engine). If that pinging can be avoided, (and also if you don't mind making a lot of NOx - high ignition temperatures will do that) then the spark ignition cycle will outperform the diesel cycle handily. Why? The fuel burns more rapidly, generating a higher temperature, and with your own argument achieving better efficiency.

Diesel fuels, when compression ignited, are already effectively "detonating", but the fuel burns too slowly to result in damage to the engine. ( You can, however, make a diesel engine "knock" by giving it too much load at too low a speed. Excessive cylinder pressure can actually lift the head away from the head gasket - I have seen this happen first hand on a experimental alternate-fuel engine I work with ).

Otherwise, for the practical considerations you've pointed out, the usual case is indeed the other way around. The lower CR used in most spark ignition engine allows avoiding knock, but results in most diesel engines easily out performing them (in an efficiency-sense).

My point is that there is an efficiency advantage inherent to the Otto cycle. Of course it is then inferior to the ideal Carnot cycle, but you can't have everything.

Diesel fuel has a greater energy density, at the cost of much greater mass. But gas has far better energy-to-weight ratio, and better overall power to weight ratio including the engine.
Outcome: Trucks, Trains and Ships use Diesel (total weight isn't critical), Light aircraft use petrol (total weight is critical). There are exceptions either way, of course.