Driving tips/good habits for better mpg IN CITY?

[UFO]

And brisk acceleration does not mean high rpm either. Shift up early for your acceleration and leave it in the highest gear for your target speed.

[HilseeJ]

Interesting.

What are the parameters for brisk acceleration? How fast should I be accelerating?

[JRMichler]

For me, brisk acceleration is what I get when I step the gas pedal about halfway down and shift at 2500 RPM. At that, I'm accelerating about the same as most other drivers.

I coast with the engine off as much as possible. All stop signs are full stop. I try to coast down to less than 20 MPH before using the brakes at a stop sign. If no traffic behind me, sometimes I'll coast down to 10 MPH.

[mechman600]

70-80% load puts you in the heart of peak efficiency. This does not mean 70-80% throttle. To get this load requires low throttle openings at low RPM and highter throttle opening at higher RPM. This is where a SG is useful, where you can monitor engine load. What I have found on my wife's Matrix is that the auto transmission kicks down to a lower gear at 80% load, regardless of RPM. So if you can learn how far you can push the throttle down to a point just before it kicks down in every RPM situation, chances are you are accelerating in the 70-80% load range.

[BHarvey]

Did 3 trips yesterday all in town, 42.9 (warmup), 45.1 and 42.7 mpg.

Don't drive the speed limit.
The closer the lights are stacked, go even slower.
Leave a massive gap, let it keep extending.

Did I say I love the short trip feature on the Eco-Ultragauga?

On my personal best tank so far with almost half tank used and showing 42.1 mpg combined.

The short trip feature is a 'must have' in my book.

[SegaSaturn]

I'm glad this thread is still going, hope it also helps other city drivers. I didn't want to make a new thread on this so I'll ask it here ... how does one calculate THEIR MPG? My car, iirc, has a 12.2 gallon tank. At 136403 miles I had 3/4 tank of gas. Now at 1/4 I am at 136530. I know I need to be at a full tank and run it close to empty but I used an online 'calculator' (filling half a tank is 5 gallons) and it showed me 44mpg...is that legitimate? ?

[HilseeJ]

Originally Posted by SegaSaturn

how does one calculate THEIR MPG?

I actually don't run through a full tank. I do it by halves.

The method I use:
===
Fill up tank.
Reset trip meter. (if you don't have one then write down your mileage)
Drive around until half tank.
Fill up tank.
Divide miles traveled by gallons that you just pumped in tank.
This is your miles per gallon.
Repeat multiple times to compensate for different pumps and average.
===
My understanding is that the first half of the tank is the most efficient as well as easier on the fuel pump. However, I'm not that mechanically inclined so I'm merely going off of posts made on this forum.

Using the same method above only running through a full tank will still be accurate.

Also realize that this will waiver from pump to pump so getting an average is the ideal thing to do. Some pumps might give a little more fuel before stopping the flow, some a little less.

Obviously topping off will skew the results.

Originally Posted by SegaSaturn

My car, iirc, has a 12.2 gallon tank. At 136403 miles I had 3/4 tank of gas. Now at 1/4 I am at 136530. I know I need to be at a full tank and run it close to empty but I used an online 'calculator' (filling half a tank is 5 gallons) and it showed me 44mpg...is that legitimate? ?

If the online calculator made the assumption that because you were at 3/4 of a tank on your gas gauge you burned 3/4 of 12.2 gallons, then no, it's not legitimate. Same applies if your gas needle was at half and the online calculator assumed that you burned half a tank.

I have traveled 115 miles and my needle was still on FULL 100%.

The method I listed at the beginning of this post is the only fool-proof method I am aware of to get an accurate mpg reading.

[BHarvey]

Originally Posted by HilseeJ

I actually don't run through a full tank. I do it by halves.

The method I use:
===
Fill up tank.
Reset trip meter. (if you don't have one then write down your mileage)
Drive around until half tank.
Fill up tank.
Divide miles traveled by gallons that you just pumped in tank.
This is your miles per gallon.
Repeat multiple times to compensate for different pumps and average.
===
My understanding is that the first half of the tank is the most efficient as well as easier on the fuel pump. However, I'm not that mechanically inclined so I'm merely going off of posts made on this forum.

Using the same method above only running through a full tank will still be accurate.

Also realize that this will waiver from pump to pump so getting an average is the ideal thing to do. Some pumps might give a little more fuel before stopping the flow, some a little less.

Obviously topping off will skew the results.



If the online calculator made the assumption that because you were at 3/4 of a tank on your gas gauge you burned 3/4 of 12.2 gallons, then no, it's not legitimate. Same applies if your gas needle was at half and the online calculator assumed that you burned half a tank.

I have traveled 115 miles and my needle was still on FULL 100%.

The method I listed at the beginning of this post is the only fool-proof method I am aware of to get an accurate mpg reading.

The problem with this method, is, say you have a 11 gallon tank.... and you have a +/-.25 gallon error
200/5=40mpg
200/5.25=38.1
200/4.75=42.1

VS.
400/10=40mpg
400/10.25=39mpg
400/9.75=41mpg

See the difference? Half the error when doing full tank.

[redpoint5]

Today I got stuck in Portland stop and go I-5 traffic again. I was averaging 32.6mpg with steady 70mph freeway cruising.

I experimented again and allowed a gap to develop in front of me while I drove the average speed. Rarely did I touch the brake, and I mostly idled in 4th gear (out of 6 total). I also counted the cars that "cut in". In 50min of stop and go traffic, 26 cars changed into my lane in front of me. People allowed the gap to exist for the most part. Sometimes a car would bounce between my lane and another as they attempted to be in the fast lane (which didn't exist). Maintaining my lane the entire time, no lane on average moved faster or slower than mine.

50min later when traffic had opened back up, my mpg had risen to 33.

Stop and go driving is more efficient than steady 70mph for my car (Acura TSX 6-speed manual).

[user removed]

I think the OP stated that he had routes with timed lights, which essentially dictates your average speed. I deal with a similar situation in my routes. 40 miles and 46 lights with the majority of them in less than half that distance. You best primary tactic is to keep the numbers of lights that make you stop to an absolute minimum, or take routes that have fewer lights.

regards
Mech