The OEM wires on the Volvo have a date stamp. It is stamped week/year. So mine are stamped 29/07, so they were actually made the 2nd week of July, 2007. Also, there are other OBD-II trip computers that can help you monitor real time/trip gas mileage.

One is the ScanGauge II and I can't remember the other. There is a Dyno Dash that does about a million things for a million dollars (about $300) but I am looking for the $60 item and will post back.

 

Here is one: PLX Kiwi - Kiwi Wifi, Kiwi Bluetooth, Kiwi MPG, Kiwi Drive Green OBD 2 Devices

The key is getting one that keeps real time, current trip, tank data and maybe the last trip data. That way you can change a few things in your driving habits to see what works best and it will cause you to stop doing things that suck down gas.

The big thing that we must remember is most of our around the town trips are less than 30 miles. If you are a lead foot, thinking that pounding another 5, 10, 15 mph will make a difference, it really doesn't. If I drive to my office like the office is on fire, I might make that 18 mile trip 2 or 3 minutes faster than I would if I drove like it was the last tank of gas I was going to be able to purchase becasuse all the stations were out. Not to mention the chances of getting a ticket. I usually catch people that blow by me at the next light. The difference between me driving 15 miles at 65 mph vs 75 mph is less than 2 minutes. Do the math. Even worse yet is racing from one traffic light to another. It's just sick!!! When you take off from a light you will get about 6 mpg until you reach your cruising speed (35/45 mph). If you can get that up to about 12 mpg you will almost double your mpg efficency. What these gauges make you do is stop forcing fuel through those injectors and take it easy.

Now when your crusing around and you need to teach someone a lession, by all means do so, but that usually happens once very 2 weeks or so. If it's a daily occurance you need theropy.

Just think, if you can increase your fuel economy 25% like I have (I was getting 21 mpg around town), your adjusted price per gallon drops from $4 per gallon to $3. Over 5,000 miles you would have saved $152. If you drive 15,000 miles per year that is about $456. Now this is hard to do but I did it anyway. Instead of driving 80 mph and getting around 23 mpg on my 900 mile trip to Albuquerque and paying $136 (gas was $3.50 at the time), I drove 65 mph and got 29 mpg, which cost me $108. So it took me another 2 hours to make the trip and saved me about $30. At the time I really needed the $30 so I was happy.

When I find that other gauge I'll post back. It was a little square thing that did monitor several things at a time with a main image w/ 3 smaller images around it. It was around $59. The thing I like about the scan gauge is that you can reset your current trip data which gives you the average mpg with the trip. I checked about 6 different highway speeds before I figured out that my sweet spot in the 960 and 850 was 62/63 mph. The real time mpg gauge just doesn't give you a 50 mile average like the current trip feature can. Unless you reset your entire system a few times which you can if you have the trip computer installed in your car. My 960 had NO fuel computer so I had to get the scangauge to give me some real time data.

 

Oh, before I forget, you may want to read some info on Hypermiling. And btw, driving close behind a truck will do nothing other than **** off the truck driver and get your windshield cracked, unless you can stay within 10 feet.

 

Here is the dang thing, took me forever. They need a webguy that can help them with their search engine stuff.
Ultra Gauge: UltraGauge Automotive Information Center and OBDII Scan Tool

 

I know you guys think I'm going crazy but here is another point. When using my ScanGauge II I usually disply the following values:
Speed / Real Time MPG / Engine Load / Engine Temp

Then from time to time I check Volts, and switch to my trip computer to monitor my current trip average mpg, yesterdays average mpg, today's mpg, and tank mpg.

Bottom line is you will at least save 5% but the average person saves about 15%. The gauge will pay for itself in 3000 miles. It will probably take about a month or two to correct your bad habbits.

 

Ok, here is my summary of what I think will help someone get better gas mileage:

1. Tune your car up. Replace plugs if they are past their life time/mileage.
2. Use the gas that your car recommends, not the minimum, the recommended octane.
3. Learn a little about hypermiling. Google it: Hypermiling :: Even without a hybrid car, no more need to compare gas prices
4. Get a mpg trip computer:
   Ultra Gauge: UltraGauge Automotive Information Center and OBDII Scan Tool
   PLX Kiwi: PLX Kiwi - Kiwi Wifi, Kiwi Bluetooth, Kiwi MPG, Kiwi Drive Green OBD 2 Devices*
   ScanGauge II: ScanGaugeII - Trip Computers + Digital Gauges + Scan Tool
5. Check to make sure that your thermostat is working properly and your engine is running at the right temperature. Another good use for a good mpg trip computer.
6. Get a K & N air filter that will fit in your normal box: K&N High Performance Air Filters, Air Intakes, & Oil Filters
7. Use full synthetic oil. DO NOT switch to synthetic oil if you suspect that your motor is worn. If you have a lot of miles do or have a compression test done first. If your motor is in good shape, synthetic oil is suppose to be even less friction and cause you to get better gas mileage. If your engine is in poor condition it may cause leaks and/or finish it off.
8. Keep your tire pressure up. Run at recommended pressure or a pound or two higher.
9. Get rid of junk you don't need in your trunk. That is not a portable storage unit. Extra weight = more load on your engine = more gas used.
10. Use a fuel injector cleaner every 10,000 miles. I have 3 cars to care for so I buy the big bottle: Lucas Fuel Treatment : Lucas Oil
11. If you have BAD O2 sensors, get them replaced.

EVERY DAY that you DO NOT do the things listed above, it IS COSING YOU MONEY. If I think of anything else, I will add it later but this should do it.

 

I would add use synthetic for transmission fluid. For injector cleaning I would recommend ultrasonic cleaning Injector Cleaning Steps

 

You think synthetic transmission fluid would help with mpg?

 

One thing I noticed about my car, its running a bit over center in temp. I will check into it, does the computer gives an actual temp readout?

 

Yes it does. So if you hook up a obd-II code reader, warm the car up and take a reading you will get actual temp. T-stat could be broken.

 

I meant the in dash computer, the ones that gives mileage, mpg, etc..
And what should be optimum temp on the s70 t5.

 

Yes, it is not uncommon. It helped with my 855T.

 

Rspi is right -- the most accurate reading is by the OBD2 real-time scanner. The gauge in the instrument cluster is rigged by Volvo (and other carmakers) not to show fluctuations. Or an aftermarket gauge would show accurate readings too.

"Dash computer" you mean the one whose display is controlled by the "Info" switch?

 

Henry
Yes, thats the one, Ive noticed theres temp, but seems to be outside temps, not the cars.
Although I could go in the garage and read the users manual???

 

You can also stay in your chair and read the on-line user manual that Volvo has:
Volvo Cars | Community | Your Volvo

No, the dash computer is a trip computer. It will NOT tell you the engine temp. The temp for these cars usually cruise at about 190 degrees. T-stat starts opening at about 182 and is fully open at 195 I think. When it's warm outside and I'm sitting somewhere, the car will reach 210 - 215 but not every day. My ScanGauge II stores top temp so I do check it sometime.

 

I am new to both this forum, and Volvos in general.

I am having some of the same issues with poor mileage. My 1997 N/A 850 is reading "bank one to rich". I have "in the last week" replaced the MAF censor as well as the plugs and both o2 censors. Last night I searched for an intake leak and found none! I visually inspected as well as a starter spray search with the car running. I have reset the ECU after every new part by leaving the battery terminal unhooked for a half hour. But after an hour or two of running is seems to come right back. Any thoughts??

 

actually this is false, trucks leave a draft a long distance behind them.

 

There are many reasons to make the car run rich. If your Fuel economy is suffering something is awry.

What are the DTCs you are getting? What's your fuel pressure reading? Have you checked your vacuum like this How to Use and Interpret a Vacuum Gauge. What is the state of your Stage 0? Do you know how to check the Coolant Temperature Sensor?

When you replaced 02 sensors, did you make sure that you connected the wires correctly?

Don't throw parts around until you go through diagnostics...

 

jesus , i run both my cars on 98 octane as apparently the fuel here in australia is too weak to run the car otherwise, ( thats what it says in the handbook)

 

Drove today about 10 mile city/pseudo highway
Jumped to 19.1 mpg but as I left the car on to get my kid out of the car seat, it started droping..it only took a few minutes but it already was at low 18...
Also noticed a bit of hesitation if I stepped on the gas after a light, but as soon as we were rolling, it was pulling strong and constant