A nice gesture, but it is only a dummy light that hardly approximates the Prius'/Camry/Lexus hybrids' consumption display.

At least Toyota is making an effort. That is a lot more than most automakers.

My family had a 1984 BMW 528e until several years ago. If you recall the "e" was supposed to stand for economy. The 528e had a fuel economy gauge with a reading (we found out later) that was basically directly proportional to engine manifold vacuum. I doubt this is effectively much better. Its not hard to calculate and display instantaneous fuel economy digitally, why don't they just do that instead of a nanny light? Oh yeah, because that has been done widely before, and that wouldn't generate any positive media.

This is good. It is simple and will modify the way some people drive, especially if gas is expensive. BMWs have had this for years - I had one and it did change my driving habits.

What would be interesting would be to go further and "green tune" the car, in the way that guys tune up cars, you could opt to tune down yours for better gas milage, like the way Ford put low rolling resistance tires on the focus.

What would be useful would be a list of best performing tyres for each car type which is kept up to data and perhaps puts the top 3 tyres in each section.

This would take quite a bit of work but would be a good job for the goveenment or the EU or someone with public funding.
- JM

mahonj,

a google search will lead to a few different studies done on tires. They don't indicate grip and handling but they do show rolling resistance. Then you go to tirerack's website and you can find lap times for different tires on the same car with the same driver and grip measurments (braking, slalom, road holding) under wet and dry conditions. Combine the two pieces of data to make the best compromise in handling vs. rolling resistance.

Some modifications for more acceleration do improve gas mileage...if you don't try to make use of the acceleration in excess of what you had before (some minor mods to get a car from a 16 sec 1/4 mile to a 15.8 sec 1/4 mile may yield a 5% improvement in fuel economy if you use the same acceleration that gets you to 16 sec). Example: lightweight rims and light weight tires of the same diameter as your stock rims and tires can allow you to accelerate at a faster rate but if you don't change your driving habits you can save some gas (with the caveat that the rims would have to have close to the same aerodynamic profile as the stock rims as well). 10% weight reduction improves gas mileage by a few percent AND will allow your car to accelerate faster (not to mention recover quicker from transitions such as a slalom or emergency lane change when someone cuts you off). Smaller serpentine belt or removal of accessory belt on the A/C gives a very small benefit in fuel economy & acceleration as well. Raising the static compression ratio gives more torque throughout the engine operational range and lower gas consumption (but if you raise it too much you need to use higher octane gas...raise it too little and the cost of custom pistons and labor far outweigh the very small fuel economy and power gains). ETC, ETC, ETC.,

This is absolutely moronic. If they were so concerned about fuel economy, then they wouldn't be driving automatics in the first place. Take the $1000 you could save by not buying an automatic and the dough you save by getting better mileage with a manual, and be happy. Plus you wouldn't have a nanny light annoying you. Regardless, no driver should need a computer to correlate the cause "pressing the GAS pedal MORE" returns the effect "MORE GAS is consumed". If they do implement this "feature" then it better be possible to disable it. I would never buy any car with this thing equipped.

Test drove the Camry Hybrid last night and had a chance to play with those feedback gauges. It's confusing at first to have all that extra information on the dash, but it's nice to be able to test driving behavior against marginal fuel economy -- basically it's a simulator/trainer for getting more out of each gallon of gas, which especially takes practice with hybrids.

My vehicle has a MPG guage, it encourages me to drive gently. It makes driving slower almost fun.
The thing I like best is getting better mpg than my friends that have cars with engines 1/2 to 3/4 the displacement of mine.

"Mark A,
Maybe the reason GM doesn't have this dummy light is that it probably would not function properly, or they couldn't rig it so that it would ever light up.
Why would GM want this? it might steer driver awareness toward environmentally considerate driving/fuel economy which is a greater priority elsewhere."

Yes GM could make this "function properly" or "light up". Witness their OLM.

The point I was making is that everything "Toyota" is automatically good, whereas everything "GM" is bad or worse. You proved my point.

More on the automatic vs. manual: Even though manuals have the potential to be more efficient than automatics in most cases, I'm not convinced that most drivers of manuals actually drive in such a way that they're more efficient. Too often they shift too late when accelerating, for example, and trade efficiency for extra power.

Isnt this the same thing that was in american cars in the 1990's when it whould give you average miles per gallon and instant economy when you hit the instant button it would show high gas millage when you were coasting or light on the gas( i had it in my dodge)
It was down right dumb

Patrick:
You are absolutely right, most gadgets considered to be performance-oriented save fuel consumption too. I want to add that independent suspension and all-disc brakes, which allows more aggressive cornering due to better road holding, also improves vehicle control when we need it most: on slippery road. It decreases road accidents and saves lives.

JRod:
Automatics usually are geared softer then manual. That compensates somehow for their mechanical inefficiency. But that does not mean sluggish performance: at low RPM torque converter multiplies torque so effectively (2 times), that from stand-still to about 40 km/h automatic outperforms manual. Manuals catch-up later, but mostly because it usually have 1 gear more then automatics. That’s why dedicated drugsters prefer automatics. Usually manual transmission is markedly more fuel efficient on cars with moderate power engines. Regular cars sold in US/Canada have more powerful engines, like 120hp per 1200 kg car. In this case fuel efficiency of automatics and manual is practically identical. 140 hp Honda Civic with 1.8 liter 140 hp engine – standard in US/Canada – makes 30/38 mpg on 5-speed manual and 30/40 mpg on 5-speed automatic.

It is absolutely untrue that slow acceleration saves gas. Gasoline engine is more efficient when it works on wider throttle. Usually that means that auto transmission upshifts at much higher RPM, which kills fuel efficiency. The best way to save fuel on acceleration is to accelerate firm (but not full gas to avoid over-riching of mixture on older cars) until RPM reaches it shifting point at light acceleration – you have to remember this RPM, then gently lift gas to provoke upshift, and accelerate further. Naturally you have to have tachometer, which on automatics is considered “performance” gadget too.

I installed fuel/air indicator on my car, which by the way indicates exact moment when injection of fuel stops completely at overrun, and when it resumes at low RPM. Adjusting my driving to prolong “no injection” mode, I managed to reduce my fuel consumption by no less then 5%, especially on mountainous highway. Automatic transmission allows more effective use of this technique.

I used to own a vehicle that featured a digital display near the rear-view mirror that allowed you to monitor both instantaneous fuel economy and a rolling average over the last 100 miles or so. I found that I only consulted it occasionally (you DO want to keep your eyes on the road, after all) but that doing so caused me to make subtle changes to my driving style that resulted in a few percent improvement in fuel economy.

Toyota's eco light (presumably green) on the dash may achieve much the same effect at a lower cost. However, drivers associate light signals on the dash (especially yellow, orange or red ones) as safety-related warnings so there is a risk that they could get distracted or annoyed by the eco light until they get used to it. It might be wise to counter that by making the transitions gradual, even if that adds some cost. In addition, a more stable rolling average mode would be welcome. After all, what you typically care about is whether your driving style earns you kudos in general rather than right now.

Note that in Austria, environmental awareness training is now reportedly part of driver's ed. As in most other EU countries, you have to be 18 to take your test and afaik you have to take a minimum number of (fairly expensive) classes from a state-certified instructor.