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I have a 2000 insight with roughly 140 k miles on it. I bought a BETTER battery a couple weeks before hybrid battery repair closed. The battery charges well and my car has a significant more amount of power.... But im only getting 45 mpg. According to the website i should be getting around 80! Does any one have any suggestions on how to improve my mpg? I was thinking it might be a computer problem or something just cuz my car is so used to getting terrible mpg with my old battery. I also have been putting water in the engine instead of coolent, could that hurt my mpg too? Thanks for the help
 

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What tires are installed and at what pressure are you running them?

Do you use the A/C regularly and if so, in ECON mode?

About what percentage of your driving distance is at highway speeds, and what highway speed do you tend to drive?

Do you let your car go into autostop when driving where stop lights exist?

Are any trouble lights illuminated on your dashboard and if so, which?

Is your 12 v. battery good?

Do you need to add water to your cooling system regularly and if so, where is the missing coolant going? Adding water to your cooling system won't decrease your fuel efficiency, but it doesn't contain the conditioners, antifreeze, antioxidants, etc., contained in coolants, so you should really be adding coolant.

There are so many things that affect fuel efficiency, so we need to know more about your driving habits and your car to try to understand why your fuel efficiency is below average.
 

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Location in your profile please.

Willie
 

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Discussion Starter #4
I have standard tires and have then at 40 psi from the last time i checked. I always drive with the ac on cuz Of the hot climate I live in.. Wat difference does the econ mode make? About 80 percent of my miles r driven on the freeway, usually at about 75 mph. My car does go into auto stop at all lights as well. My maintenance required light has been on since I bought the car... The coolent does not leak, I just spent 3k on this battery and am hurting on money right now. I believe my 12 v battery is okay cuz I drove the car around with a broken hybrid battery for about a year before I could afford to replace it.
 

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Is the car a manual or automatic? That can make a big difference on expectations.

When was the last time your oil was changed and what type was it?

Alignment?

Terrain?

Traffic flow?
 

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I have standard tires and have then at 40 psi from the last time i checked.
If by standard, you mean 165/65R14 Bridgestone RE-92's, then you aren't losing any fuel efficiency due to tires. You could probably improve your fuel efficiency by a tiny bit with higher inflation pressure but at the expense of some comfort.

I always drive with the ac on cuz Of the hot climate I live in..
Then you won't get the 80 mpg that you've read about. The original owner of my car drove with the A/C always on and never in ECON mode. Most of his driving was urban. His lifetime fuel efficiency was 49 mpg. When I bought his car, I pumped up the tires from ~30 psi to 44F/41R, didn't run the A/C routinely, and allowed autostop at all traffic lights. My fuel efficiency with the same car was 62 mpg in urban driving. Most of the improvement was due to my not running the A/C.

Wat difference does the econ mode make?
The engine won't go into autostop mode unless the A/C is in ECON mode. But driving most of your miles on the highway, this shouldn't make much difference.

About 80 percent of my miles r driven on the freeway, usually at about 75 mph.
That's too fast for the engine to easily enter its most efficient mode, lean burn mode, with the A/C on. When I drive about 55 mph, I can average about 80 mpg without A/C. When I drive about 70 mph, I can average about 70 mpg w/o A/C.

My maintenance required light has been on since I bought the car...
Search for "maintenance required light" in the Google search field along the upper left edge of this page to find the simple instructions for turning off the maintenance required light.

I think your high average speed and your high A/C use are the primary reasons why your fuel efficiency is low.
 

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Discussion Starter #7
The car is manual transmition and I have not had the alignment done since I bought the car. But I have changed my oil recently with high grade hybrid oil ( don't remember name). I have been using premium gas over the last couple months as well.. That's better for the engine and should help my mpg right? Thanks for the info on the tires and ac, I have learned more about my car in he last couple hours than i had over the entire last year.
 

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Make sure the oil is 0w20 and forget about the premium gas. Use the low octane grade without alcohol. Premium branded gas is fine but extra octane just makes the fuel burn slower to prevent detonation.

Alan
 

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The car is manual transmition and I have not had the alignment done since I bought the car. But I have changed my oil recently with high grade hybrid oil ( don't remember name). I have been using premium gas over the last couple months as well.. That's better for the engine and should help my mpg right? Thanks for the info on the tires and ac, I have learned more about my car in he last couple hours than i had over the entire last year.
As AClewell mentioned, that is patently false. Octane rating has absolutely nothing to do with fuel economy or being "better" for your engine. In fact, running high octane fuel in an engine not meant for high octane fuel is undesirable. Due to the aforementioned slower burning, it can actually increase carbon deposits. Further, high octane fuel can contain up to 2% less energy than lower octane fuel. The octane rating is simply a measurement of the fuel's ability to resist spontaneous ignition. Nothing more, nothing less.

It's the use of A/C and the fast speeds on the highway that are destroying your fuel economy. If you have tires other than the P165/65R14 RE92s, that will also have a significant impact.
 

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More specifically on the tires, if they are not the exact brand and size listed above you will probably be losing about 10 mpg.

Speed kills....your mpg. If you are pinching pennies, try running 10 mph slower if possible.

How long have you had the car? Watch closely the fuel consumption gauge (fcd). You can maximize your mpg by looking at it all the time.
 

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Yeah, keep an eye on your instant fcd. That'll tell you Where your losing mpg. Get an idea of what your averaging at a steady cruise.

Correct me where i'm wrong, but i try to get the highest octane for acceleration purposes only. In all the cars i've driven whatever power it had seemed to come on faster. It needs all the power it can get.
 

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Hi Barak, 45mpg at 75mph and a/c on is about right., suggest just for fun you try driving with 55 mph and a/c off on a level highway. clear the mpg indicator and check how are you doing then. and if there is no traffic, you can try slowing down to
45mph , you should be able to see 80-90 mpg. also watch for a "lean burn" mode .It happens in speeds 20-67 and you can see it when the car keeps the same speed with 75-125 mpg on the bar. There is a slight jerk when the car enters and exits of lean burn.

Also you probably should clean your EGR plate, there are many posts on this subject, you will easily gain +5mpg if it is clogged now and you clean it..

another thing is check if all aero panels under the engine are still there.

there about a dozen more simple things you can find here nicely explained, all of them saving you 2-3 mpg here and there....

but the a/c I think is enemy #1 on the mpg...~15-20 mpg penalty....
 

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I gassed up yesterday on the way home. I am at 107 miles, 80.3 mpg, with my cvt. I would think that a manual should be able to get 80 to 90 mpg at 55 on level ground. I agree, the ac will cut at least 15 mpg off.
 

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Yep, AC and high speeds are killing you. Here in AZ with AC cranking if i am mostly running in the city I'm getting around 45 MPG, the constant stopping just kills MPG. Partly because I don't use Autostop and also I tend to keep the RPM's high to keep from using much assist to save the battery. Even if I can get some time on hwy at 60-65 with AC I can bump it up to mid 50's.

Now in the winter here when not using the AC just running around town with some mixed 65 mph freeway speeds I can easily get 63-65 mpg. While being careful I easily got a couple of 70+ mpg tanks when not using AC.

So it is not unheard of to see swings from mid 40s to mid 60s in this car just because of weather, speed and driver mood.
 

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On high vs. low octane fuel, pretty sure the Insight's fuel requirement is '89 octane or higher.' Also, the Insight has a knock sensor, right?, and it automatically retards ignition timing to prevent pre-ignition, such as from low octane fuel, heavy load, etc. If you run higher octane fuel, it stands to reason that you'd be able to run the engine at a higher load without pre-ignition and with less timing retardation... Higher octane fuel IS probably better, though probably not worth the extra cost...
 

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On high vs. low octane fuel, pretty sure the Insight's fuel requirement is '89 octane or higher.' Also, the Insight has a knock sensor, right?, and it automatically retards ignition timing to prevent pre-ignition, such as from low octane fuel, heavy load, etc. If you run higher octane fuel, it stands to reason that you'd be able to run the engine at a higher load without pre-ignition and with less timing retardation... Higher octane fuel IS probably better, though probably not worth the extra cost...
No, the owner's manual specifies 87 octane or higher. IMO, there is absolutely nothing to be gained in power, acceleration, engine life of fuel economy by going to a higher grade.

Many owners want the very best for their cars, the best oil, the best repair shop, the best wax, and the best gas - but equating "best" gas with octane is a mistake. From a power viewpoint you are better running the lowest octane recommended by the manufacturer. As Eli said, higher octanes contain less energy.

There is only one small exception that I can think of and that is the case of very high mileage cars. There is a rational arguement to be made that high mileage cars may need a bit more octane, since their pistons and compustion chamber probably have some buildup of carbon, raising the compression ratio. Even in this case, the engine knock sensor sould retard the timeing a bit to compensate if knock was sensed. I doubt that it would occur with any great frequency, meaning that 87 is still ok. The owner's manual does not say anything like, "Use 89 octane after 150,000 miles."
 

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No, the owner's manual specifies 87 octane or higher. IMO, there is absolutely nothing to be gained in power, acceleration, engine life of fuel economy by going to a higher grade.
From the Insight Central Knowledge Base:
"The North American owner's manual says to use on "regular" 87 octane or higher gasoline. The service manual, however, indicates that 91 octane (95 ROZ) gasoline should be used for best performance. The German owner's manual also says that you should use "premium" 95 ROZ (91 octane) gasoline. It goes on to say that the Insight can be driven with lower ROZ gasoline, but power may be reduced."

This makes sense to me. To prevent potentially damaging preignition knocking, our Insights have a knock sensor that retards the ignition timing when knocking is detected. Retarding the timing reduces the power output somewhat, but knocking would likely occur only under full throttle or when lugging without assist (e.g., when running without the IMA battery pack). If you were racing an Insight where full throttle operation would be normal, higher octane gasoline would likely produce slightly more power (less knocking, less ignition timing retardation) and would be worth the additional cost.

But what percentage of our driving time do most of us spend in full throttle operation? Is this worth spending a considerable premium over 87 octane gasoline to purchase higher octane gasoline?
 

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From the Insight Central Knowledge Base:
"The North American owner's manual says to use on "regular" 87 octane or higher gasoline. The service manual, however, indicates that 91 octane (95 ROZ) gasoline should be used for best performance. The German owner's manual also says that you should use "premium" 95 ROZ (91 octane) gasoline. It goes on to say that the Insight can be driven with lower ROZ gasoline, but power may be reduced."
I own a hard copy of the Service Manual and I can find not a single mention anywhere of fuel requirements. Anyone can write anything on the internet;)

If you have first hand knowledge of the section and page in the service manual where fuel requirements are mentioned at all, please provide the ref.

The service manual does not in general touch on the types of material covered in the owners manual, that being the operation of the vehicle - to include fuel requirements. The service manual is devoted to "heavy" subjects such as how to diagnose failures, rebuilding components and component tolerances. Fuel requirements are not covered that I can find. I'd be happy to be proven wrong;)
 

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91 ron

If you have first hand knowledge of the section and page in the service manual where fuel requirements are mentioned at all, please provide the ref.
I'm not the person you're asking, but I'm happy to respond. On page 2-10 of the Insight 2000 Service Manual (North America edition), in the table "Design Specifications", I read: "ENGINE | Fuel Required | Premium UNLEADED gasoline with a Research Octane Number (RON) of 91 or higher"

I know of no other reference to fuel, but I can't assert that there isn't one. I've not read it cover to cover (only had my Insight ten years :D ).

I use a 99 RON fuel, but that's just to get better detergents than those used in the 95 RON that's the standard offering on English forecourts.

Martin.
 

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Jime:
Service manual.......Page 2-10....Engine spec.

Willie
 
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