Quote:
Originally Posted by JCL
I used a SWAG (OK, some judgement involved) for my 30 hp figure. But I wasn't thinking 70 mph; the average on my vehicle over several years is closer to 36 mph, at which speed 30 hp may actually be pretty close. But then I don't have rear seat heaters. The only point was that the 5 or so % is another hit against mileage, added to increased idling time, less engine efficiency when cold, and all the other things that bring mileage down in winter.
What is surprising to me is that we have all these posters who didn't know that their mileage would drop when it got cold out. It has been doing so for the last 100 years or so.
BCR: You have to allow engineers to be engineers every now and then  |
I know, but it is sooooo painful.
How do you account for head or tailwinds, air density differences, summer/winter fuel additives, average speed or terrain. Seems like the only way to be close to accurate is for that particular X5 that the formula is based.
What would you say the +- range is for accuracy?