Never braked from San Jose to palo alto with 55~65mph and end up with only 42MPG?

[inuvik]

One thing to consider is that even though you don’t normally use the “AC/Power Reducer/Snowflake” button much in the winter turning your air control to defroster only runs the AC compressor just the same as you did.

[Mark]

One thing to consider is that even though you don’t normally use the “AC/Power Reducer/Snowflake” button much in the winter turning your air control to defroster only runs the AC compressor just the same as you did.

I am assuming the above comment was for Fummins, maybe?

I can't say that I have ever owned a vehicle with automatic climate controls. I drive my parent's vehicles that have it, however. All of my personal vehicles have been manual climate controls.

Some like my former 2000 Honda CR-V had the A/C automatically kick in whenever you switched to window defrost only mode. If you didn't want A/C on during window defrost, you would simply turn it off with the A/C button.

The A/C does not automatically kick in when switching over to window defrost mode on my 2017 Mirage ES (manual controls) or my 2011 Subaru Forester 2.5X (manual controls). If I want the A/C to help clear the windshield, I have to turn it on manually. I actually prefer it this way.

It would be easy to go 5+ months without the A/C ever being used on my Mirage. If I remember, I try to turn the A/C on for a few minutes every couple weeks. Letting the A/C sit idle for months on end is not good for the seals and such.

[Eggman]

I average high 30s on the way to work and low 50s on the way home, all level ground same traffic

I suspect warmer temperatures contribute to the afternoon fuel economy gains.

[Fummins]

Yes, the snowflake/ac power reducer icon does turn on automatically when you hit defrost, unless windows are fogging up I leave it off though. Still can't break 40mpg.

[highwire]

The different tires could be part of the explanation.

Nothing has less rolling resistance than a worn out Low Rolling Resistance (LRR) tire. So at the point your original tires needed to be replaced, they were actually producing the least amount of rolling resistance...and the highest fuel mileage.

Even if you replaced them with the original style of tire, you would see a slight drop in mileage because the new tires have more tread (and more rolling resistance). You installed new tires...but you also changed to tires that were not low rolling resistance.

So from a tire standpoint, you went from the least rolling resistance (a worn out LRR tire) to the most resistance (a new non-LRR tire). In real terms...that one change might have cost you as much as 3-4 mpg.



There are lots of variables involved. And you are right...this car is sensitive to certain changes in driving conditions. I'll toss out a few ideas...

Is that a drive with a lot of hills? If so, that could account for some of it. This car doesn't like to climb hills. If you were climbing hills with the cruise control on, that would be even worse.

Were you running the air conditioning? That really kills your mileage.

70-75mph? Forget about it...that's a mileage killer, too. The good mileage starts to fade above 60mph.

Do you have a CVT or a 5-speed? The 5-speed is going to be slightly better for fuel mileage.

Have the temperatures been cooler than usual out there? If so, that can also reduce your mileage.

Are you Ubering around with 3 400-pound passengers?

The weight limit for passengers is 892lbs (3 passengers and 1 driver averaging 200lbs each with 92lbs of cargo).
2019 Mitsubishi Mirage weight by trims Curb weight Gross weight Payload Capacity
[43096] ES 4dr Hatchback 2018 lbs. 2910 lbs. 892 lbs.
https://autotk.com/weight/mitsubishi/mirage/#2019
The user manual has some slightly different ways of reaching that limit, I recall.

I also recommend checking the tires. I am looking for an accurate guage though, because my pen sized one seems to require multiple tests, and i lose air everytime I test it. I would like to put air in it so it will be good for three months. Estimating it will lose 1 PSI per month. But Is there any risk in having more air on one tire compared to another one?

Using brakes are just as important as not using them, but also driving slower is less wear and tear on the brakes because they won't be needed as much. https://www.topgear.com.ph/features/...brakes-adv-con

[nickels]

The weight limit for passengers is 892lbs (3 passengers and 1 driver averaging 200lbs each with 92lbs of cargo).
2019 Mitsubishi Mirage weight by trims Curb weight Gross weight Payload Capacity
[43096] ES 4dr Hatchback 2018 lbs. 2910 lbs. 892 lbs.
https://autotk.com/weight/mitsubishi/mirage/#2019
The user manual has some slightly different ways of reaching that limit, I recall.

I also recommend checking the tires. I am looking for an accurate guage though, because my pen sized one seems to require multiple tests, and i lose air everytime I test it. I would like to put air in it so it will be good for three months. Estimating it will lose 1 PSI per month. But Is there any risk in having more air on one tire compared to another one?

Using brakes are just as important as not using them, but also driving slower is less wear and tear on the brakes because they won't be needed as much. https://www.topgear.com.ph/features/...brakes-adv-con

Losing air every time you test is a symptom of HOW LITTLE air these tires hold.

When I had my Jeep, if I wanted to go from 27 psi to 20, I had to remove the valve core and wait 10 seconds before rethreading it. In a mirage, simply touching the valve stem can drop you 5 psi in a couple seconds. There's a bit of a volume difference between a 35/12.5/15 and a 22.5/6.5/14...

[nickels]

And for myself, I find the best balance of handling and economy and tire wear patterns running the front tires at 38 psi and the rears at 31. Wet traction begins to reduce drastically above 40 psi, and fuel economy gains start to slow down greatly above 36 or so.

The rear tires have almost no weight on them, they get squirrelly if I match front to rear pressures, and they wear on the centre as well. I mean, the rear tires on our car support as much weight as a fat guy riding a unicycle so, no need to drive them to crazy pressures.

[highwire]

Losing air every time you test is a symptom of HOW LITTLE air these tires hold.

When I had my Jeep, if I wanted to go from 27 psi to 20, I had to remove the valve core and wait 10 seconds before rethreading it. In a mirage, simply touching the valve stem can drop you 5 psi in a couple seconds. There's a bit of a volume difference between a 35/12.5/15 and a 22.5/6.5/14...

Thanks for all this info, I hadn't thought about volume, and I didn't think it would lose more PSI each second because of that when testing it. I was having trouble believing my guage when it read nearly 20PSI before adding more so it looked normal again- no sag and not a blimp either.

[highwire]

And for myself, I find the best balance of handling and economy and tire wear patterns running the front tires at 38 psi and the rears at 31. Wet traction begins to reduce drastically above 40 psi, and fuel economy gains start to slow down greatly above 36 or so.

The rear tires have almost no weight on them, they get squirrelly if I match front to rear pressures, and they wear on the centre as well. I mean, the rear tires on our car support as much weight as a fat guy riding a unicycle so, no need to drive them to crazy pressures.

Thanks for this info! I was wondering what could contribute to that squirrelly tendency on windy or even non-windy days.

[Fozziekyu]

I tried one bottle of Techron , unfortunately I feel nothing has changed ,I guess this is just how Mirage is

but I find out Costco give me bad MPG while Shell give me best MPG, I got a 27mpg with no traffic at all in SF City.... lowest in history

Shell could get my car reach 45mpg in highway and Costco will only make 36mpg in a similar trip, not sure why though