With the gas prices going up daily..and my 850 turbo requiring at least 91 octane..I wanted some suggestions on how I can improve gas mileage on my car..I have 85500 miles on the car and last tuneup was at 58000

What parts would make the biggest difference in mileage after replacement.plugs, wires, 02 sensors ..???


Thanks
Joe

You could try using your boost gauge like one of those '70s fuel mileage gauges. Don't watch it all the time, but try to get used to how it feels to accelerate without going up into the boost range.
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3 8s & 2 7s 725,000 miles total

Buy a stick..I consitently get 28-33.

Regards,

Nate

Here's the EPA's list of things that affect fuel economy and by how much.

> What parts would make the biggest difference in mileage after replacement.

A manual gearbox????

Apart from that you won't see much improvement by changing bits as long as the car is running properly. The biggest influence on fuel consumption is simply your right foot.

If you want to improve your milage then the most important part is your driving style. Use moderate throttle openings, accelerate gently, let the car coast as long as possible and use the brakes as little as possible.

Look ahead and in traffic and conciously plan your driving so you avoid as much braking and accelerating as possible. Try to maintain a constant speed as much as possible and also run a few mph below the speed limit.

The fun part also is that you should try to take corners with as little speed loss as possible. Judge the corners and see if you can take some at for instance a constant 40mph where you would normally brake down to 30mph before the corner.

Also do not let the car idle for longer periods (eg. when scraping ice off of the windows), but start and drive or stop it as soon as possible.

Bye, Arno.

It's due for a 90K/30K service, every 30K miles (or 2 yrs). New plugs, air filter and it wouldn't hurt to think about dist cap, rotor and ignition wires.
Monitor your present mileage and how it's running.
Whatever you do/don't do, don't use lower octane fuels as that'll make both your perforamance and mileage suffer.
Both of my cars use premium too, I just try not thinking about it as there's nothing I can really do as long as my cars tune-up related parts are up to snuff.

> Whatever you do/don't do, don't use lower octane fuels
> as that'll make both your perforamance and mileage suffer.

Performance, yes. Fuel economy, not so clear. Fuel economy is related to the "fuel heating value" or specific energy content of the gasoline. In general, it's true that premium gas has a slightly higher fuel heating value than regular gas, but it averages only about 0.7%, and there's lots of variation possible depending on formulation. For those premium formulations that use oxygenated blends (many cities; all California), the fuel heating value is lower (about 2.7%). For winter blends, it is also lower. In many cases, regular gas takes the lead.

For more casual reading, the folks at Chevron have assembled lots of technical detail about gasoline: http://www.chevron.com/prodserv/fuels/bulletin/motorgas/ch1a.shtml

Gerald C

Say what you will but I've heard that from VCNA people (instructors, etc) since turbos first came out in Volvos (early 80s).
Theory: In a Volvo turbo if you use lower octane fuel, it'll knock (probably won't be audible to you), but the knock sensor then causes the ECU to retard timing thus performance is less and thus gas mileage drops too. All Volvo turbo engines are suppose to run premium fuel. I've never questioned it and I'm not so cheap as to even worry about a few cents either.

I feel your pain, I paid $1.99 for premium gas when on vacation in New Hampshire, and pay $1.88 regularly at home for premium gas. They don't sell 91 just 87, 89, 93 at most stations so I make it a point to alternate half tanks of 93 and 89 if I need to save some $$, I figure the half tank of 89 will mix with 93 when I fill it up to average out to 91 so I'm all set. Besides, Volvo says minimum acceptable octane is 87 (not that i'd ever use it) and 91 octane is reccommended for "optimum performance", so u could even get away with 89 all the time. Of course this is in a N/A engine, not sure the reccommended and minimum for the T-5.
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I'd say you're on the right track, tune it up new distributor and plugs, and check O2 sensors, wouldn't want it mixing rich. Also if need be adjust your driving habits, just a thought

Thanks everybody for the great suggestions..I think I would definitely look into tuning the car and then adjusting my driving habits.

thank