Gas mileage question (vehicle, sedan, MPG, tuning)

[rlrl]

The most dismal gas mileage range to be expected in normal driving I had ever seen in a CR's test was the 1973 Ford Country Sedan wagon, clocked at 7-14 mpg. (By contrast the same years LTD sedan clocked at 8-16 mpg range).

My question is since the average of these two ranges is 10.5 mpg, does this mean that the owner would most of the time average 10.5 mpg for the life of the car?

[M3 Mitch]

Depends on who the owner is, how he uses the car. If it was me driving the car to/from work, 40 miles mostly in top gear, it would probably get close to 14. Once I got around to re-tuning it some, probably better than that.

But some wretch in NYC who knows diddly about cars, who only took it to a shop when it wouldn't start, who was frequently starting it to drive it to the other side of the street so they could sweep the curb, might well get worse than 7.

In fairness to Ford, probably the reason this car is a champion guzzler is that they put a higher numerical gear diff in it, so it would have at least some pep, given the body coming up overweight and the engine probably not meeting their original goal for power. But I'm guessing here.

Some of these old V8 land yachts can be improved *a lot* with a set of block-hugger headers, dual exhausts, a low-RPM oriented aluminum intake, and a 4-bbl instead of the stock 2-bbl. In terms of both mileage and performance.

At the same time, high teens for mileage is about all you are going to get, and you'll have to drive it right to get that. But for a road trip with 2-3 buds along to split gas with, they come into their own.

[johnrex62]

The simple answer is no. Even if the normal distribution of driving was such that the city/highway driving actually resulted in even average of the two ratings, the engine efficiencies will change as the vehicle ages and the mechanicals wear.

As M3 Mitch stated, driving habits greatly affect actual mileage and will affect what any individual person will achieve under a set of conditions and will likely vary significantly from the published figures. Then the ratio of driving conditions will affect the actual average in a much more complex way that a simple average will produce.

Sorry, but there is no quick way to apply those mileage ratings to your actual driving style, they are only a baseline to give you a fair comparison under standard conditions. Your actual mileage may vary, as they say.