1990 Volvo 740 GL

Discussion in 'Start Your Journey Here' started by wreckingcru, Nov 10, 2006.

  1. wreckingcru

    wreckingcru New Member

    Hey all!

    Hoping you can all help me improve my mpg on the Volvo.

    I commute 40 mi each way to/from work -> Long Island Expressway in NY.

    I usually drive about 65-67mph going to work (since I have reach there in a particular time frame), try not to brake too hard, use cruise control, and stick to the middle lane.

    Driving back home, I do about 62-65 mph with the same rules.

    When I first started following <70, I got 27mph which is pretty decent. But ever since the first 2-3 fuel ups, I've been doing worse than before - prob hitting the low 20s (if at all).

    There is nothing heavy in the car, no roof rack, single driver (thin, 180lbs), and not a (particularly) hard braker.

    Any help?
     
  2. Chuck

    Chuck just the messenger

    Welcome to CleanMPG!

    Be sure to check the air in the tires, the oil in the crankcase...

    If memory serves me correct - Volvo was one of the first to introduce overdrive - probably want to stay in it as much as possible.
     
  3. wreckingcru

    wreckingcru New Member

    Thanks for the initial suggestions...

    My Volvo is the GL version (no Overdrive) ...
    I think I'm going to take the suggestion of over-inflating the tires to approx 40psi (recommended is 33-35) ...

    Sorry, but I'm kinda blank on a lot of car terminology...so you might have to spell it out for me...:confused:
     
  4. brick

    brick Answers to "that guy."

    I had a 1985 GLE wagon as my first car. I would say the biggest thing working against you is aero drag, which comes from a CD in the range of 0.40 or even higher. The only way to overcome that is to slow down and give yourself a little extra time to get there. This is one car where driving 55mph is truly and measurably better than driving 65mph. (I can certainly understand that traffic won't always allow that, though.) Weight is also an issue (in the range of 3400lb I believe?) but is more important for stop & go driving than highway driving.

    If memory serves, the automatic transmission on that car should be an AW71 or AW71L, where the L stands for lockup torque convertor. That's a big deal for FE because it directly links the engine to the transmission rather than transmitting the power through the fluid all the time. You should feel it engage once you get into 4th gear at speed. If you don't it's either not working or not equipped. Unfortunately I can't remember if the 71L was introduced until '90 or '91. Nothing you can do about it either way, I guess. (Mine was a manual version with the strange 4-speed plus overdrive transmission, which did a good job.)

    In terms of technique, your #1 goal on LIE (after safety) is keeping your momentum. The main point of not braking hard is to get out of the throttle as early as possible, thus using less fuel. The other point is not to bleed off kinetic energy that you will have to re-gain later using the engine. To you this means planning as far ahead as you can. On the highway you want to leave as much distance between you and the next car as you can manage. That distance keeps you from having to slam on the brakes every time that car slows down. Instead you can just watch for brake lights and coast down, reducing the odds that you will need to hit the brakes.

    You will read a lot of talk about people using fuel economy displays such as the ScanGauge to get feedback about how we are doing. Unfortunately this isn't an option for you since the car is non OBD-II compliant. (It's just too old.) There is a product called the SuperMID that might work but I don't know much about it. But there is a very simple and inexpensive option, which is to install a vacuum gauge. That gives you instantaneous feedback about how hard the engine is working. More vacuum = less fuel being burned.

    Finally, and I really should have said this first, make sure you are up on your maintenance. A 17 year old car is much more likely to be running inefficiently than a 2 year old car. Clean injectors are important, as are intact vacuum lines and a functioning O2 sensor. These are things that you have to inspect yourself since there is no "check engine" light with trouble codes on that vintage car. You should also be especially watchful of the brakes, as those calipers have a tendence to sieze, killing not only your pads/rotors but your fuel economy. Pulling to one side or another is the first symptom, followed by an unearthly grinding sound under braking which means that you have already chewed the pad down to the bolts. Take it from someone who knows, this sucks. Keeping the calipers lubricated is good preventative maintenance. If you haven't already, I would recommend buying a good shop manual to help you out with all of this maintenance stuff.

    The best I ever did in my '85 was 30mpg. I didn't know what I was doing, though. I think she would have been good for a little more under the right conditions.
     
    Last edited: Nov 10, 2006
  5. tbaleno

    tbaleno Well-Known Member

    what is LIE?
     
  6. brick

    brick Answers to "that guy."

    Long Island Expressway...I should have said the LIE
     
  7. hobbit

    hobbit He who posts articles

    And if the typical counterargument to leaving lots of space
    occurs to you, "but then everybody will jump into the gap!", realize
    that sure, a couple of people might use the gap to perform
    maneuvers they need to but overall it *helps* traffic flow.
    Especially around entrances/exits where drivers so notably and
    miserably fail to do the "zipper thing". You can not only give
    yourself plenty of workspace, you can encourage more competent
    merging by not being yet another object in everyone's way...
    .
    _H*
     

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