Highway driving types, how you accelerate, your climate, road conditions etc.

Whether you measure in US miles or CDN miles...

I guess it just seems strange to me that those things would make that big of a difference.

Even what brand of gas you buy, or what brand of tires, regardless of pressure. Type and condition of the air filter, oil type, oil filter type, they all play into it.

My guess on the 92 SSEi is based on the higher friction valvetrain, btw.

In my 2000, I get 33-34mpg at 70mph.

Ok, for a few seconds on the DIC maybe, then the Mustang pulls up alongside.......

With the TC locked up in OD, you'll get almost as good as a 92-95. But in hilly or mountainous terrain, the 92-95 will get you in the mileage realm. The power and torque is delivered at a lower rpm, so the engines don't have to work as hard.

That thing is weird. When I step on it, the DIC reads 6mpg heheheh

my 93 bonneville sse is getting at the best, 19 mpg... of course, i just changed the air filter and will most likely need to change o2 sensors, but i'm jealous of you 23-25 mpg range guys... I wish i could get those kind of mpg... any suggestions?

dave

I pulled out the reciepts and, yes, the O2 sensor was replaced. The mileage has been the same since rebuild so I guess the O2 sensor is still probably good. Thanks, I guess my mileage is not anything to worry about, then.

Oh, rebuild?? Did you have the cylinders honed or bored at all??

I think alot of it has to do with temperature and wind direction as well as road conditions.
Here'* a good example. I recently took a trip from San Diego to San Jose, about 500mile trip, and got 25.5 MPG. On the return trip, same road and distance, I got 28.5 MPG. I drove the same speed both ways, cruise control on. The biggest difference was, temperature was hotter on the return trip and different brand of gas. Perhaps different wind directions played apart as well. The traffic through Los Angeles was heavier going up as well, so I'm sure that played a part.

Anyone that says they get more than 17 city in a supercharged or over 19 city in a NA is probably exaggerating. True city driving is alot of stop and go traffic, with little sustained higher speeds. I've been monitoring my city mileage lately, and this is true city driving. I have a 7 mile commute from home to work which takes an average 20minutes, with zero highway miles, and the best I got so far with extreme granny driving technique is 16.5 MPG. I found an alternate route that avoids most traffic lights, but still has stop signs every 1/2 to 1 mile, and that is better, since I only stop for a couple seconds at each sign, with about 30 MPH between each. The other route, has lights, and I stop at maybe half of them, with each stop lasting 1 to 2 minutes, and speeds up to 45 MPH in between. I believe the route with less lights is better, because excessive idling at lights kills gas mileage and the engine temp gets hotter. Also, the route with all stop signs, still takes the same amount of time total 20minutes, and usually beats the traffic light route, even though the speed is lower.