I am averaging 20mpg city driving in a 95 850 GTL non-turbo 5 speed with 57k miles, is that normal or should I be expecting more? I just bought the car and it runs great, Im just surprised at how bad it is on gas at the moment.

also im running 87 grade in it.

 

Depending on traffic congestion that isn't horribly out of line for the city. I tend to average around 24 to 25 mpg on my '94 non turbo 5 speed on combined city and highway driving and the city commutes are short and largely non congested. On pure highway I get a fuzz above 30 mpg running at 70 to 75 MPH.

...Lee

 

That is slightly low but there are a couple thing you can do...

When was the last time a stage 0 was done?
What Gas are you using?

Also read this entire thread over--->https://volvoforums.com/forum/volvo-...ove-mpg-52856/

 

Here I go again...

You should use 91+ octane because the car was designed as a high compression motor and 91 will help.

 

What rspi said. You can run 87 octane but you'll get reduced performance and mileage (knock sensors will sense the lower octane and retard ignition timing). The N/A engine is designed for premium (10.5:1 compression ratio).

Also this time of year (if it's winter where you are..) lots of locales start selling ethanol blends; this also hurts gas mileage considerably.

Beyond that, since you just bought it, i would do a compression test just to see where it's at. If it's low, that will also hurt mileage (and performance). And stage 0 tune would be in order...

Of course depends on how much your foot is in it too, but average for these cars is about 25 mpg in city; maybe 30 or more on hwy.

 

Are you sure that the N/A needs 91? Almost all posts that I've read said that only the turbo engines are hurt using 87. Would the mileage improvement of 91 be worth the additional cost? I've yet to get better than 18 MPG city in my '93 854, and I average ~17. It doesn't seem like it is knocking or low on power from retarded timing...

(My thermostat was broken open and my spark plugs were dirty, I just replaced them. Might explain the low mileage.)

 

Let see, in order...
Yes. Not true. Up to you.

And yes, thermostat being broken open will keep engine from getting up to operating temperature which will definitely use more gas. More importantly, if this condition is allowed to continue long term, could wash the cylinder walls of lubrication and cause pre-mature engine wear.

 

I guess I will have to try premium for my next tank. Thanks for the confirmation.

 

Run it the next 3 tanks. The computer will adjust during the 1st tank and you'll likely know on the 2nd tank.

BTW, Volvo claims that these cars should get 21 / 30 so you're not far off.

 

My 97 850 T wagon has dropped to about 10-12 mpg around town and about 20 on the highway. Smells like it is running rich and recently noticed soot around the exhaust on the bumper. I am at wits end to find out why. No codes, checked all vacuum lines. Has only ben a few thousand miles since the last major tuneup. I will try a tank of premium but would be shocked to see a 100 % increase in mgp.

 

My guess would be that your spark plug gap needs to be checked. Also, read this post and thread: https://volvoforums.com/forum/volvo-...e3/#post268165