Gas vs diesel

Hey lads,
So I've been doing some research about diesels vs gasoline and came across this interesting quote. "A 10HP diesel is equivalent to a 14HP gasoline". So I thought huh, that's sort of interesting and put this theory to the test. Basically the above numbers mean that you can have up to 29% less horsepower and still keep up (that is in the same car"). My friend drives a ford Taurus with 155hp, and me and him raced up to 100kmph. I kept up next to him the whole time. So lets do some math 155x0.29=44.95 (lets round this to 45). 0.29 is the percentage of horsepower we can have less of and still keep up. 155-45 is equal to 110hp, so in other words, this theory is pretty correct considering he weighs about 400lbs more than me.

Now I know this is all theory because it doesn't take torque or weight really into consideration, but I was just wondering what your thoughts are on this and if it's probably just coincidence that we're the same speed.

The horsepower figures you give are only the peak power output of the engines. They are only making that much power when at a certain RPM and full throttle.

See if you can find a graph of the torque output of your engine and for his engine.

Horsepower is calculated using torque and RPM.

Plug some numbers into this calculator and see what you get: http://www.metaris.com/hp-relations.php

For example, let's say your engine produces 177 lb-ft at 2000 RPM. That gives 67 HP. How much torque does the Ford Taurus produce at 2000 RPM? I bet it's less.

Post results for the curious.

The argument of which is better, torque or HP, is an age old argument.
We are sold vehicles based on HP, however, this is a single metric and highly lacking.

I would bet that our diesel vehicles could pull more load more miles at a higher speed than most any other midsize vehicle with a gas engine built today.
This is my thought anyhow.

There's a reason people buy diesel trucks over gasoline and most of it has to do with efficiency and load hauling capability with a few for the flexibility of fuels able to be burned, very few.

A lot of this equation has to do with the transmission also.
Gasoline contains approximately 124,000 BTU/Gal
Diesel contains approximately 139,000 BTU/Gal

So every gallon of diesel contains about 15,000 more BTU's than gasoline.
Which is about 12% more energy by volume which is part of the reason for the difference.

Another part of the reason is that a gasoline engine must run rich where our diesel engines can run lean and get more of the available energy out of the fuel.

Couple this with higher compression and less blow-by and you're nearly at the total of 29% difference you read.

So yes, this is completely logical.