FEOA Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
10,892 Posts
Discussion Starter · #1 ·
Well, recently I've noticed that my car REALLY blows on the highway. I can get about 500km to a tank on 80km/h roads, but as soon as I use the highway, I'm getting only like 350 to 400km to a tank. I was wondering if there was anything that I can do to better my mileage, I've noticed that the one problem with the highway is that when going bout 120km/h my car is fairly high RPM's, and I'm going to be taking highways every day starting in september for bout an hour a day or more.
 

·
Registered
Joined
·
15,385 Posts
Auto or manual? How high are the RPM's?

There are so many things that can cause this, such as low tire pressure or a coolant temperature sensor that is going bad, et.c that we would need more info.
 

·
Registered
Joined
·
914 Posts
120 km/hr is not really all that fast... I'd /assume/ your problem is, if you have an auto, that it's not shifting into the higher gears properly. If it's a manual and you're already in the higher gear and driving conservatively.. Dunno what to say. Some cars just get worse mileage than others, due to engine wear, maintanence, etc. :\ Keep your fuel system/filter clean?
 

·
Registered
Joined
·
8,446 Posts
Certainly sounds like an auto. Either that or you don't know how to drive a manual.

Is your check engine light on?

Both times that my O2 sensor went, it got to the point that I was going through fuel at an astonishing rate (like 100 km to a tank). The sensor fails in an engine "safe" way such that excessive fuel is fed to the engine to avoid a lean, excessively hot (dangerous) combustion condition.

It's possible you have a developing case of O2-sensor-with-the-shitz. However, you should notice an inability to maintain high speed if this is the case.
 

·
Registered
Joined
·
2,709 Posts
Well, if your O2 sensor is bad, (as high said) not only will your ECU default to an absurdly rich mixture, but you'll also get a check engine light, and you may flood the engine a little. And I know that you can't flood an EFI engine, but it's just a misnomer.

If I were in your shoes, here's what I'd do:

1. First check the codes. You can do this yourself with an analog voltmeter and a paperclip.
2. Check the plug gaps on all four cylinders, and see if the plugs are in good shape
3. Check the tire pressure
4. Check the compression in each cylinder. If you're running really rich, the injectors will wash the oil off the cylinder walls and the rings of the pistons won't seal correctly. You'll see this in low compression numbers. You may have also burned a valve and you're leaking like crazy in one of the cylinders.
5. Check to see that your transmission is shifting correctly. It's a 4 speed in the automatic transmission, and in 4th gear, it has an automatic lockup, which feels like a 5th gear, but it's really just the torque converter making a mechanical connection with the flywheel (I think... I dunno autos that well). Either way, try running your shifter indicator in overdrive and see if that makes any difference. Also experiment with different throttle positions.
6. Do a pressure test on your intake. Basically this just entails fitting a PVC cleanout cap where the MAS is, then drilling a shraeder valve into the cleanout cap. The hook it up to an air compressor, and pump in about 13psi and check for leaks with some soapy water.

Also, another thing to check is all of your fluids.
You also want to check the exhaust tip to make sure that it isn't black with carbon soot buildups.
 

·
Registered
Joined
·
8,446 Posts
I'm either getting old or soft or both...Siragan, as much as your avatar makes me giggle like a school girl every time I see it, I wonder if it's a bit too harsh. Sorry, must have had a moment of weakness.
 

·
Registered
Joined
·
10,892 Posts
Discussion Starter · #7 ·
OK, well, it's an auto, check engine light never been on, I always run it in OD, but that "5th gear" doesn't kick in untill about 125 or so, sometimes more, sometimes less, as for the RPM's, they're at about 3500 around the 115 - 120 km/h mark. I know tire pressure is all good, and otherwise it drives great, like as I said, no problem doing 100 or 80, and it has no problem maintaining a speed of 145 or 150 on the highway if need be. As for the rest of that stuff, I will attempt to check it out myself - I try and do my work myself, but I have a reliable mechanic / friend who does my work because I rarely have time (still costs a fair chunk, but it's better than me wrecking stuff)
 

·
Registered
Joined
·
10,892 Posts
Discussion Starter · #8 ·
Never mind this post, I'm a dumbass and figured it all out (I believe, will respond again if I do have the same problem), you can just point fingers and laugh at me!!! I just realised that last time I went was all open roads, so the car was about 140 or 150 the enitre way (bout 4000rpm the entire drive), and this time there was a lot of stop and go due to accidents and all that BS, so I think my car should be fine, I was just really tired and I wasn't thinking - I had just been partying the night before, and then got up at 6 to go to Wonderland!!! But if this is still obscene gas mileage, let me know and I'll still check that stuff out!
 

·
Registered
Joined
·
8,446 Posts
There have been a few previous posts where people have stated their fuel economy. I keep a close eye on mine, 'cos I'm a cheap bastard. I think your fuel economy sucks my arse a bit.

From what I've seen, my beater (91 LX manual) has about the highest mileage engine on this board, or pretty close to it. I still get 600 km to a tank (~ 43 L normal fill) when burning summer gas and not towing; the best I ever got was just over 700 km, but that was three or four years ago, in one non-stop all-highway trip going 120-130 km/hr the whole way. Most of the time, because I have no friends, I'm alone in the car with little cargo. I tow a boat regularly and it is easy to see the hit my fuel economy takes then.

Because I live at the edge of civilization, I benefit from very little stop and go traffic, which can definitely kick you in the wallet.

Nonetheless, I think you could do better, even though yours is an an auto (barfs). Aside from all the other brilliant ideas already listed, make sure your alignment is good (can make a huge difference) and you change your air filter regularly. And lose some weight.
 

·
Registered
Joined
·
8,446 Posts
I tow a 400-500 lb boat all over Gawd's green earth.

The Escort does a decent job towing reasonable loads. But the old fuel economy takes a beating when towing. I just keep my speed at about 90 km/hr when towing. The stated fuel economy was when NOT towing. I'd guess that I get 400 km to a tank if towing the boat for an entire tank.
 
1 - 11 of 11 Posts
Top