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Hey guys I have found that my 98 lesabre will only get just about 200kms or less 160kms from a FULL tank to a half tank, I am just wanting to know if this sounds right to some of you guys, I must say I feel it could be a little better than that, suggested ideas? Thanks !

Your fuel gauge is very subjective.

Fill your car, and write down your mileage. Next time you re-fuel, check your mileage, do the math, and report back here with a good description of your driving habits (light/heavy foot, 40% city, 60% highway, etc).

Most cars on this forum should hit 28-30 highway in good condition. With a little attention to detail, every 3800 (supercharged or not) should be able to hit 30. Some of us do even better than that.

It could be you're noticing the difference that cold weather driving makes. Running rich for warm up will drop mileage drastically.

I think it's normal to get 350 kms to a tank with round town driving. 600 on the highway after warm up.

I'm getting around low 20's mpg (US gallon) HIGHWAY with this cold snap we've been having.

200km to the half tank (real level, not based on the gauge) is about right for city driving in the cold with a bit of leadfooting here and there.

Well, if your fuel gauge is like mine, that's not right at all unless you're doing a lot of idling or short trips before the car ever gets to closed loop.

With my style of driving, I get about 350 kms per half tank, every time.
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You live in AL, he lives in Ontario. There's your difference.

Pretty sure rogers9c1 isn't too far out from where I am.

(oh and look, salt on the road )

Source: http://www.cyburbia.org/forums/showthread.php?t=17433

Imagine that, gridlocked and bumper to bumper, from 7:30 to 10am and 3:30 to 7pm, every day. Even most weekends. The closest highway interchange/onramp by my house happens to be one of the busiest stretches of highway in the world - and there's your difference between Ontario and Alabama. Also why I rarely get more than 340 miles (550km) to a tank with mostly "highway" driving. When I do road trips out into the boonies, 31+mpg is easy in the summer, and I've bested 35.

This last tank for me in Medicine Hat was only 300 kms to the Low fuel light. Warm up time in the cold sucks.
I generally do about 400 to a tank mixed highway/town. On the highway I can pull 30 pretty easily.

My last long highway trip was 32 mpg going from SC to Buffalo, NY in 20*F weather the whole way. Then again my car's modded for fuel mileage and I drive very conservatively by this forum's standards.

Your mileage is entirely possible in cold weather diddling around town. It takes ~7-8 minutes of partial-throttle operation for my car to get above 160* F, and about 8-9 minutes to get to its normal temperature of 175*F (180* thermostat). Running around town your car doesn't get a chance to warm up.

Try adding a grille/radiator block of some sort to speed up warmup. I have about 65-70% of my radiator blocked right now with no overheating.

This may seem silly but I don't know how to calculate my Mpgs I have never tried it before, nor do I know how to do the math part of it, math is not my strong point, I some one give me a quick break down of the calculations i have to do Thanks.
My driving habits are bad right now i do know that I warm the car up for about 20 minuets in the morning and then maybe 20 or so before I leave work, I do have a little bit of a heavy foot and I also don't really do much highway driving, the long road to work is 80km a hour, and I use the highway to some time boot across town quick but not often, do I need to drive to car until the low light comes on? i almost never let it get below the half line, the car is costing me about $20CND a day.

Miles/gallon = # of miles traveled/gallons used. You can also do liters/100 km.

Idling the car for 40 minutes a day explains why your gas consumption rate (fuel mileage) is so bad. That's 40 minutes your car is burning gas going nowhere.

Try blocking off the radiator to speed up warmup, don't use the heater until the temperature gauge is near normal, and wear an extra layer when driving around town.

Lastly, reduce your idling time. Idle less and drive it more. You'll also heat the car faster by driving than by idling.

20 minutes is your problem right there.

I don't do more than two or three in the coldest weather, and after that I tread lightly until things are up to temp.

Check to see if your oxygen sensor is working properly. If it is registering LEAN it will start thinking it needs to add more fuel...therefore you use more gas

londonontman wrote:Check to see if your oxygen sensor is working properly. If it is registering LEAN it will start thinking it needs to add more fuel...therefore you use more gas

funny you say that as my cars CEL has come on with this code P0171 Lean Burn on Bank 1. this might just have some thing to do with it?

i usualy get 32mpg

I just filled up the 94 SSEi yesterday. It went 425 km and took $70 cdn to fill on a mix of city (40 mph) and highway (80 mph) driving.

I got 33 mpg the other day on an 800 mile roadtrip.

And currently my mileage is 17 mpg in urban-jungle driving.

With O2 sensor problems I can see why your mileage is bad.

hmm I guess I will have to start looking into getting some new ac delco oxygen sensors, I am jealous of your guys mileage! any other mantince related items you guys can think of that might give me a wee little more mpg's?

Here's the Maintenance List. Figure out what hasn't been done, and do it.

Brand Suggestions are in the parentheses.

• 1987-2005 Bonneville / Buick 3800 Maintenance List
  
  Run Seafoam through gasoline and intake every 5,000 miles. One pint of Seafoam in a half tank of fuel is a good mix. The intake is optional, but recommended.
  
  Grease: Ball Joints, Tie Rods Every 8-10k ( Green Grease recommended)
  Air Filter Every 15k (Amsoil EaA, Purolator PureONE)
  PCV Valve Every 30k
  MAF Sensor Element Cleaning/TB Cleaning Every 50k viewtopic.php?f=48&t=1661
  Fuel Filter Every 15-25k (Purolator, AC Delco, WIX)
  Spark Plugs Every 30-50k (NGK TR55 or Autolite 605) (Never Bosch)
  Ignition Wires Every 30-50k (Napa Belden, AC Delco, Autolite Pro, NGK) (Never Taylor or Bosch)
  Oil & Filter Every 5-6k or Every 6 months (Mobil1 or Amsoil)(Mobil1, Purolator PureONE, Amsoil EaO or WIX) (Never Fram) viewtopic.php?f=45&t=214
  *Conventional Oil Every 3k/3 months(Pennzoil with a WIX (Napa), Delco or Purolator filter)
  Transmission Flush Every 15-20k (Always make sure filter is changed when flushed)
  Cooling System Flush Every 25-50k or 3-5 Years (Peak or Prestone Green Coolant Only) (Never Dexcool)
  Oxygen Sensor Every 80-100k (30k for non-heated) (AC Delco or Denso) (Absolutely never Bosch) viewtopic.php?f=48&t=794
  Accessory Belt Inspect every 15k, replace every 100k, or as needed
  Cabin Air Filter Inspect and Replace every 15k, or as needed in dusty conditions. (Note: 00+ Only)
  Evap Core Cleaning Whenever Needed (Note: 99 and older only) viewtopic.php?f=45&t=2432
  
  *Special Considerations*
  All 3800s, LG3, LN3, L27, L36, L26, L67 & L32, especially important on vehicles factory installed with orange Havoline Dexcool Antifreeze/Coolant: http://www.dex-cool.net/
  Lower Intake Manifold Gasket Replacement, every 80-100k (ignorance of this can allow coolant to enter your engine oil, this happening can cause irreversible lower engine damage, requiring replacement of subject engine)
  
  Series II, Naturally Aspirated, RPO:L36:
  Upper Intake Manifold Plenum Replacement, Every 80-100k (ignorance of this can allow coolant to enter your intake manifold, possible damage to occur can be hydrolock, irreversible damage to emissions devices, misfires, etc. Most times, engine replacement is required if ignored long enough.) viewtopic.php?f=53&t=1061
  
  Series I, II, III RPO Code L67 & L32:
  Change Supercharger Oil; Every 30-50k. (Intense Racing or GM Dealer) viewtopic.php?f=56&t=1690
  Supercharger Belt; Inspect Every 15k, Replace Every 100k or as needed.
  
  Rev. 1/12/2010 By 00Beast

And Ed goes for the maintenance list!

I'm lucky if I get 17-18 mpg on an all-city tank. It's all stop-and-go short-trip driving that maybe tops 35 mph a few times around my place nearby downtown Columbia, SC.