mileage just disappearing

[arcosine]

Good point on airing up the tires. Adding a warm air intake helps my mpg in the cold weather.

[GRU]

i wouldn't worry about overheating your engine...if it doesn't over heat in the summer, you can block 95% of the grill opening and it will be cooler than in the middle of the summer....If it does, the fan will turn on and suck the cold air from under the car or anywhere else since it's much colder now...

What's your average speed on your trips? what's the average distance you travel at a time?

[ever_green]

average speed is ~30mph because of dozen stops lights/traffic etc. the trip is about 15miles one way or 30minutes. summer mileage was 24.5mpg on the dot, now it's about 20mpg even though i do less rushhour time.

highway cruising at 70mph displays 26mpg when it used to be near 30mpg. car used to get real hot in summer here when temps were in 90s. coolant reached 103'c or 220'f. one reason why i got rid of the underhood insulation pad.

i will be reseting my ECU back to factory settings tomorrow and will see the difference.

[serialk11r]

Originally Posted by arcosine

I don't like over square engines. Fine for performance, but not fuel economy. combustion surface area increases buy the bore squared. 100 mm bore has 50% more area than a 80 mm bore.

• Prius:
1,497 cc 1.5 liters in-line 4 front engine with 75.0 mm bore, 84.7 mm stroke, 13.0 compression ratio.

Honda CRX HF: Engine Bore/Stroke 75.0x84.5mm

Saturn S series: 82 Bore× 90 mm stroke

Honda Insight: 72 bore × 81.5 mm stroke

Subaru EJ25

Displacement: 2457 cc
Bore: 99.5 mm
Stroke: 79.0 mm

That's what intuition tells us and it is a correct trend, but read the 1ZZ-FE development paper, where they compare different bore/stroke ratios. The difference is not as big as you'd think.

[arcosine]

I see nothing outstanding here:

Gas Mileage of 2012 Vehicles by BMW

[serialk11r]

Originally Posted by arcosine

I see nothing outstanding here:

Gas Mileage of 2012 Vehicles by BMW

What about it? BMWs are big heavy cars overall.

[ever_green]

i think 34mpg for a 3500lbs 328i with ~265 horses (read here why the power is underated) is pretty impressive. i just think that for a car that can haul 5 people comfortably, has a nice size trunk, 0-60 of 5s and handling of a sports car 34mpg is wow. plus BMW never inflates their numbers and if anything it always underrates its specs.

in canada the 320i model is available which is a 180hp version that gets 5.3l/100km or 44mpg. that's better than a hyundai elantra isn't it?
http://www.auto123.com/en/bmw/3-seri...rid=1120800110

In europe they have diesel models that have no problem getting even better mileage.

[Ecky]

Originally Posted by ever_green

i think 34mpg for a 3500lbs 328i with ~265 horses (read here why the power is underated) is pretty impressive. i just think that for a car that can haul 5 people comfortably, has a nice size trunk, 0-60 of 5s and handling of a sports car 34mpg is wow. plus BMW never inflates their numbers and if anything it always underrates its specs.

in canada the 320i model is available which is a 180hp version that gets 5.3l/100km or 44mpg. that's better than a hyundai elantra isn't it?
http://www.auto123.com/en/bmw/3-seri...rid=1120800110

In europe they have diesel models that have no problem getting even better mileage.

I believe modern engines are rated with all accessories attached and running, ie AC, electrical load, which just about accounts for the difference.