Gas mileage
I've a 98 Corolla with 6700 miles on it. It still
doesn't give me the gas mileages posted on edmund's
site(28 in the city and 36 on the highway).
Recently I drove to a place 100 miles from Austin.
I was on cruise for the most part of the trip. I
got only about 31 mpg !!! I used to own a 96 Saturn
SL1 which used to give me more than 40mpg with
cruise on the highway.
So, is this something I need to check with the
dealer right away ? What could have possibly gone
wrong with the car ?
I already talked to a dealer over the phone once.
They mentioned that the 28/36 mileages were under
ideal conditions and the actuals may vary with
driving conditions etc. etc.
Thanks in advance for any feed back.
Ven
doesn't give me the gas mileages posted on edmund's
site(28 in the city and 36 on the highway).
Recently I drove to a place 100 miles from Austin.
I was on cruise for the most part of the trip. I
got only about 31 mpg !!! I used to own a 96 Saturn
SL1 which used to give me more than 40mpg with
cruise on the highway.
So, is this something I need to check with the
dealer right away ? What could have possibly gone
wrong with the car ?
I already talked to a dealer over the phone once.
They mentioned that the 28/36 mileages were under
ideal conditions and the actuals may vary with
driving conditions etc. etc.
Thanks in advance for any feed back.
Ven
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I bought a 99 corolla a month ago. At the first fill-up, I calculated 26.7mpg (mostly non-peak hours on Los Angeles freeways). I was told that a brand new car will not get it's optimum gas mileage. My 2nd, 3rd, and 4th fill-up were 35.5,
35.2, and 31.5 mpg respectively.
If you read the window sticker of the corolla, it will say in big prints 28/36 city/highway. But in the small print it says that actual mileage will vary with options, driving conditions, driver habit, and vehicle condition. It also says in small print that most cars in this class will achieve 23-33mpg in the city, and 30-42mpg on the highway.
What do you usuall average on your corolla? 31mpg is not great, but it's also not all that bad. When you compare the mileage of your Saturn to your Corolla, are the conditions the same? For example: the load you're carrying, traffic, hills, etc.
I'd say it's about as good as it's going to get,and 31 mpg is quite good. There's nothing wrong with the car. You might gain some improvement by checking tire pressure and inflating to maximum, using synthetic oil for faster warmups (less time on rich settings) and paying attention to driving habits. For instance, cruise control can often decrease mileage (LKF---little known fact). I'd say if you did all those three things, you could gain 1-2 mpg. Otherwise, be content, it's within specs.
I always thought that cruise control gives you better mileage until I read the last few posts. From what you said, it sounds as if cruise control works OK if the highway is flat and not hilly at all.
I also have another question regarding mileage on my 1999 LS400. I had a 1998 ES300 for about a year before trading it in for the 1999 LS400. For the one year that I owned the ES300, I got very good mileage with the car i.e. 25 MPG overall which is the same as or 1 mile off the sticker of the 1998 ES300.
I have the LS400 for about 2 months now. So far, I only got about 21 MPG at best (about 3 or 4 miles off the sticker's of the car). I haven't changed my driving habit nor the route that I take to go to work. Any idea why this is the case ? Thanks.
If I had such a car, I wouldn't even look at the gas figures. The "fun" part of it would erase any passing thoughts of economy.
Manufacturer's use some kind of test cycle to determine mileage, and yes, it's under fairly ideal conditions.
How you drive counts for a lot.. I have a standing bet with friends that i can get better gas mileage from their car then they can...no radical tricks, either...no shutting off the engine or coasting...just driving in your bare feet would help a little actually, but i don't recommend it on snowy days....tire pressure is very important too, and hardly anyone thinks of that...
THe mileage figures you see reported (from the EPA) are conducted in a lab that is set for "ideal" atmospheric conditions. In fact, it's not even a test for mileage. It's a fuel usage analysis based on the amount of emissions from the tailpipe. This is why you are always warned to use EPA figures for comparison only, and not to expect that mileage from the vehicle you drive. Because of public outcry that the numbers were unrealistic, the EPA even reduces the "public" figures.
Here is the number calculation that is used - we'll use a 1999 "Edmund SE" sedan
EPA test results by emissions analysis:
26 mpg city
38 mpg highway
The EPA combined figure that tha manufacturer uses for their Corporate Average Fuel Economy (CAFE):
2/3 city + 1/3 highway = 30 mpg
The EPA "public" figures - what you see on the sticker:
90% of city - 23 mpg
78% of highway - 30 mpg
In my example above, you can see that Edmunds can sell all the SE sedans they want, because the combined mpg figure is well above the CAFE requirement of 27.5 mpg. They can thus sell an equal number of cars that only get a combined value of 25 mpg. The truck CAFE is only 20.7 mpg - this is why you see so many V6 and V8 SUVs - they are balanced by 4 and 6 cylinder mini-trucks.
The next year I tried it again, it was ONLY about 10 degrees during the 1987 trip. I filled up in Omaha, set the cruise control and made it almost to Denver (I think that tank yielded about 510 miles). The only way I have been able to rationalize getting 25% better mileage on those two tanks was a combination of the following:
1) Altitude, less wind resistance against the car (running at a steady 70mph).
2) Turbo, while the air outside the engine was thinner, the turbo kept the air pressure inside "just right".
3) Cold air, I have had two turbo cars, and they were always faster and got better mileage in cold weather. I assume that because of the cold(er) charge entering the intake manifold, the computer was able to keep the engine settings a little more aggressive than at warmer temperatures.
Regards,
Shipo
I am not a physicist, but I have studied the basic physics of a turbo charged engine. Maybe I have this all wrong, but based upon what I have learned about turbo charged engines, there is virtually no loss of power (just slightly more turbo lag) at moderate altitudes. At any given steady speed, the turbine will spin faster at moderate altitude vs. sea level keeping the intake manifold pressure virtually the same. In essence, down stream of the turbo, the engine will operate at virtually the same efficiency as at sea level. That being the case, with the engine producing power just as efficiently as always but with less dense air to push the car's body through, the vehicle should get better mileage.
Did I miss something?
Regards,
Shipo
I took both of my turbo cars up to around 12,000 (Loveland and Independence) and you are totally correct, lower mileage and power, BUT not as much as a normally aspirated car with a similar power rating.
Both of my cars had boost gauges on the dash, it was very interesting to watch as the gauge would ever so slowly move it's way up the scale as the turbine would claw for every molecule of air it could find. Talk about "Turbo Lag" WOW, it seemed like it would take a full minute for the turbo to get wound up at very high altitude.
Ahhhh, the good old days, now I commute in NYC traffic every day :-(.
Regards,
Shipo
-maintain proper tire pressure, maintain the engine well, don't run the A/C, try to keep as steady a speed as is possible, when you have to accelerate do so smoothly and moderately, use the manufacturer-recommended octane rating of fuel.
I've noticed lower gas mileage at 55 than 75mph too. Not that THAT stops me of course ;-)
I just bought a 99 Silverado and run a fuel check in it. A 458 mile trip with speeds from 40 to 65, averaging more around 50, and got 20.1 mpg. I concider this to be very good. The old truck used to get around 9.
Daimler chrysler were recently quoted (in CAR magazine of britain) that 1/7 of the fuel consumption of a car is spent keeping all of a cars electrical systems running (engine management, abs, AC, stereo, gadgets, etc..). Needless to say this is a pretty big chunk of the fuel consumption. Of course some systems are critical but using as little electrical power as possible should help. I wonder if cruise control might actually cost more fuel due to the previously stated reasons and because it uses more power than is necessary. I don't need cruise in London but it might affect some of you guys. Lets look forward to the higher voltage (more cost effective as less energy is bled off) systems of the future.
last fall. I decided to use a new fuel additive that someone had told me about. By the way the car has 115,000 miles, tranny was rebuilt at 100,000 miles. It was mostly highway miles so the average was 22 mpg on the first tank ( it was premium fuel ) without the additive. I then put it in a full tank of premium fuel. At times my lead foot wife was running at speeds of 65 to 90 most of the way. The air was not on and she doesn't like the cruise. On that tank the numbers showed that the mileage was 28 mpg. Needless to say I've used it ever since, and have great results.
street sleeper
I own a 98 LS400 (basically the same car as the 99) with 2100 miles. The mileage you're averaging is about the same for my car also (I normally cruise about 80 MPH on the highway). However, I once tried this experiment after filling up: The commute was from Pelham, NY to Fairfield,CT (approximately 52 miles). I set the cruise at 55 MPH and drove in the slow lane. What I discovered was, that I was able to attain a highway mileage of 26.8 MPG clearly surpassing the EPA Highway mileage of 25 MPG.
So it's possible to get the government estimated MPG ratings for that car provided that you stay within the speed limit. But , who wants to do that.
I have since confirmed that all Chrysler products with that 4-Speed and Cruise Control do in fact use the transmission to help maintain speed when going downhill.
Regards,
Shipo
Depending on terrain, yes, cruise control can give you worse gas mileage, especially on uphill runs....on the straight and level with no traffic, it will probably improve mileage.
I'm tired and rambling right now. I feel like Jerry Seinfeld is eating my brain. What's the deal with that!
Suspect fuel economy in an engine designed for high octane could be adversly effected by low octane fuel...... but my greater concerns would be around overheating (related to spark retard) and ping and potentially pre-ignition.
Try Bosch platinum spark plugs. I believe they've helped a small bit for both Acura's I've had.
The highest efficiency is achieved at the lowest rpm combined with the highest vacuum. This depends on what kind of road you're traveling. Going down hills, put it in high gear so the revs are lower. Going up hills, if you find your foot down at the floor on the accelerator, shift into lower gear to "let the tranny do more work for you."
your higher mileage is probably the result of taking advantage of the lower rpm efficiency of a diesel engine. Driving this way with a gas engine might have the opposite effect, or not matter as much. I've often observed cruise control causing worse fuel mileage, since the driver gets lazy and doesn't downshift when they should.