Hacker News Reader

Comment by professorTuring | Hacker News Reader

I can remember a video (though I can't find it) where Top Gear (or a program like that) compares a Cayenne vs a diesel small car in a travel.

They had to travel from one city to another (using autobahns) and arriving as fast as they legally can and they will take cost, time and comfort considerations.

I won't spoil which one wins just in case you find the video =)

View on HN

I think I can take a guess. I drove different cars in my life, but I've driven a Land Rover LR3 with a 4.4 V8 petrol engine on the German Autobahn, and most recently a Nissan Qashqai with a 1.6 diesel engine. At 100-120mph(160-200km/h) Land Rover was using less fuel per 100km. In the city or at lower speeds the Qashqai was using less.

It's all about the power - at high speeds that massive V8 engine was still very relaxed, at 200km/h it was doing 3500rpm, while the 1.6 diesel hits that at around 140km/h, so anything above that speed is super inefficient.

It's also about gearing. I used to own '99 and '01 Corvettes about 10 years ago; I could easily cruise at 80-100mph on Illinois interstates with the engine almost at idle because of the transmission's gear ratios (6-speed manual).

>It's also about gearing.

True, but gearing and power are two sides of the same coin. You can't have tall gears if the engine doesn't have enough power to move the vehicle or sustain speeds on the highway.

Those Corvettes have a 0.50 ratio for 6th, which is basically unheard of.

Reply on news.ycombinator.com