I have a 94 850 non-turbo that is getting horrible gas mileage. I had a new used engine put in with 77k miles on it. Before I had that put in I was getting between 25-30mpg and now I'm lucky to get 20mpg. Is there anything I can check or replace that will help this out? If something similar is posted somewhere, please direct me because I searched back a few pages and couldn't find anything. Thanks for the help.

 

Are those hwy or city driving specs? If city, 20 is decent, I get 20-21 if I don't stomp the gas on green lights. Highway I get 24-26. I shouldn't say I get this mileage, my wife does. I like to use the turbo too muchhttps://volvoforums.com/micons/m9.gif

If you were getting 30, holy cow dude, I'd post the question too! But I think now you may be on average mpg.
95 850 Turbo Wagon.

 

If the car otherwise seems to run good the first place I would look on a non turbo is the airbox thermostat. If it hasn't been replaced it has almost certainly failed and it is drawing in hot air all of the time. I just jammed mine to the cold side.

The extra power and better mileage was immediate.

...Lee

 

20mpg is on the interstate with the cruise control set right at 70mph. City driving is around 15mpg. Not good at all. I'll have to check that airbox thingy. I did replace the "normal" thermostat this winter when my heater stopped heating my car.

 

I have a stick so my final drive ratio is a tad higher but I routinely get 30 - 31 MPG on the highway at 70 to 80 MPH.

A good thread on the airbox thermostat is here, it has some pictures of what is going on as well:

http://www.matthewsvolvosite.com/cha...pic.php?t=8830

...Lee

 

When was the last complete tune up? Plugs, wires, cap, etc.? Those can have a huge effect on gas mileage. Also, when was the last time you changed your airfilter? A good clean filter can add some mpg's as well.

I would start with a basic tune up and air filter if you don't know the last time they were done and go from there.

 

See my 2nd reply at:

https://volvoforums.com/m_48928/tm.htm


JPN

 

My last tune up was a little less than a year ago when the "new" used engine was put in. He replaced belts and plugs and filters.
And my check engine light has been on since then...but that's a different story. If I took it to a Volvo shop, what can I expect to spend on a full tune-up?

 

Why would you want to go to a Volvo shop to do a tune up? It´s just a matter of buying a tune up kit and installing the parts. It is very simple and you do not need any "special" tools.

 

Do you still have the service receipt/report that tells you exactly what parts they replaced?


JPN

 

I would do in order....

1. Check the airbox thermostat

2. Check the tire pressure and set to about 35 psi all around (low tire pressure, even 3-4 pounds will cause quite a drop in fuel economy)

3. Check for fuel leaks

4. Do a full tune up (use OEM volvo plugs, and MANN filters) a good place for parts is fcpgroton.com, ipdusa.com, or autohausaz.com

5. Keep us posted.

Glenn