Poor MPG for my 2006 2.5T S60 at 89K

[mrbrian200]

Buy economy car then. Mighty and thirsty 2.5T is mighty and thirsty even 10 years later

Old School!

One of the things I noticed when I was initially mulling over makes/models to consider buying-- in the used mid end lux market, the models that hold their value better tend to be those with better econ, specifically the Acura TL and Lexus ES 300/330s. But both of those were no go's for me. Because they hold their value I would have been looking at early 2000s. Both of those had back breaking problems during those years. Early 2000s TL (and Accord V6s) -rotten transmission. Lexus early drive wire in the early 2000s -unacceptably slow/delayed throttle response for which there is no known fix.

Limited production volume models (like Volvo) under $100k this long term resale value can affect new vehicle sales even if the original purchasers aren't themselves concerned with econ or long term reliability: People in this price range are still concerned with not losing their ass on the thing when they trade it in a few years down. If they truly had money to burn with zero regard they'd be looking at super high end class like Bentley, Ferrari, etc.

The FWD 2.5T delivers on the highway. And if you just take it easy it isn't at all bad around town either. Low rate of catastrophic powertrain failures: any adept driveway mechanic should be able to correct relatively minor issues that will pop up from time to time (mostly electrical/sensor/management). I think these get skipped over a lot because some of the powertrain configurations were gas hogs and most people look at the EPA ratings (not real world reports submitted by owners) and don't realize there was one configuration that was pretty darn good in this respect. One site I was looking at separated the FWD S60 2.5 and had enough owner reports to show a curve with most cars in 'average condition' getting around 30-32 on the highway, but at the top end of the curve, some were reporting up around 40. And there were enough of them reporting up there to convince me it wasn't a fluke, like the Chrysler cloud cars with the mits 2.8, EPA ratings don't look all that impressive but if everything's just right they push up around 40 on the highway too. For me, that's good enough.

[vtl]

The FWD 2.5T delivers on the highway. And if you just take it easy it isn't at all bad around town either. Low rate of catastrophic powertrain failures: any adept driveway mechanic should be able to correct relatively minor issues that will pop up from time to time (mostly electrical/sensor/management).

Yeah, sure... I keep records for everything I spend on the cars (see links below), cost analysis says that in 4.5 year and 81k miles my car cost me $39740 =) $13k purchase price, $12k gas, $2k tires, everything else is parts (I do all work myself) and maintenance. Another purchase price was put into parts. And this is not the end - I'm pouring presidents heads into the car right now, because new Volvo failed my expectations.

[abscate]

Ouch, that's brutal

I think we paid 25k for the 99 in 2000 with 20 k miles on it.

I did a major refurb in 2013 and put 3k in parts in it. Otherwise it's been fluids tires and brakes.

Now at 200k miles. I think it has not only been the cheapest to run, it's my favorite j

Don’t worry about fuel economy. Wirth the proxy war between the US and RUSSIA hit as Hades, gas will be under $2 a gallon soon.

[mrbrian200]

I second that OUCH. Fuel/standard maintenance aside I'd be a little upset too if I spent $13k in parts over a mere 80k miles on a car with under 200k on it. I doubt spending anywhere near that much on the S60 for the entire life of the car (reasonable to expect between 250-500k miles before some catastrophic failure, most likely the trans). But I really like the SPAs, the current S60 will likely be relegated as a spare/2nd vehicle or sold long before it approaches that mileage.

[vtl]

Technically speaking, it drives like new, because suspension/steering/shafts/etc are new I can't buy this car new, so I do what I can with this one.

[precopster]

The average speed is one of the tellers. Mine was 32 kph (19mph) over 6 months. If I get onto freeways or tollways there is always a number of traffic lights awaiting at either end. I leave home outside of peak times and I avoid evening snarls. I'd hate to see my speed average (and fuel consumption) if I was caught in traffic daily.

It would be interesting to do short term average speed resets in conjunction with fuel consumption average resets. If the driving style, load carried and route and time of route taken are all very similar the fuel consumption should drop with an increase in average speed.

[matthew1]

Beginning with a certain speed* where wind resistance is by far the largest drag on efficiency, mpg should go down exponentially** with speed.

* 40mph? 50? I don't know. Somewhere in there drivetrain inefficiency becomes negligible compared to wind resistance.
** square

[matthew1]

Or rather, the energy required to move the car rises exponentially... I'm guessing this translates to mpg. At least it's roughly comparable.

[precopster]

The sweet spot for most modern cars is around 90-95kph where low revs/gearing and that drag coefficient unite in harmony.

When Citroen released their CX Pallas in 1974 it was one of the most aerodynamic and fuel efficient production cars at high speed with around 0.36CD (unfortunately it was never sold in North America).

The S60 achieves 0.28CD and is still one of the world's most slippery designs.

[EngineeringBloke]

So, I am a spirited driver. When I look at the speed tracking and MPG (instantaneous) tracking on my Torque app, I see the effect of the 19 traffic lights on my 8 mile route to work. Some of those take several cycles to get through. And here, if you do not keep up with the person in front, people cut in, so that gaps get filled, although I have to admit that I like to 'keep up'. That ends up resulting in a fair amount of acceleration and then braking - hardly ideal for MPG.

Boston is an old city and has had a lot of recent growth in the city and suburbs. There is significant traffic congestion, even at weekends and the rush hours are very long. I still like living in the area. Part of my drive is a hilly, wooded parkway with many beautiful volcanic outcroppings and a lake and pond.

I am engaged, but courteous, when I drive and pay attention to other drivers and to the road.

Anyway, I was thinking about what mrbrian200 said earlier about feathering the gas, and I tried it earlier last week. I did see a 2 or more MPG improvement, so I have been keeping at it and am pleased with the MPG and more relaxed driving.

My mechanic is a great guy. He works on different cars but has been accommodating with my requests and installing various parts I failed to have the energy to put in myself. He asked me to delay my service as he was so busy recently, but he got to it last Tuesday.
- He inspected and tightened my suspension and the clunking on bumps has gone away.
- He also installed a Bosch upstream O2 sensor (part 17137) for me - one of the auto part chains had it for about $90. As I drove home, I noticed an improvement in the car. I was seeing marked better MPG, and also the car felt as if it was half the weight it had been. There had been no check engine light and Torque had not found any stored codes. Still I think this sensor was not working properly. I would have like to see if I could have gotten any info from Dice/Vida that showed something was off, but I am glad I overcame my thoughts that replacing the sensor would make no difference.

I now find that the car has a nice balance between better MPG and lots of power when I want it. I saw 30 MPG when I went for an evening drive. For my commute in, I saw 16 MPG compared to the 12 or so from before. I have not had the chance to verify the acceleration but my 0-60 is less than the 9 seconds it was.

I had noticed that when I cruised downhill with my foot off the throttle, I used to see the instant MPG go to 99.9 on the dash display, but that had not been happening lately. Now that is restored, too.

I am interested to see what some long highway trips are like. A few years ago, I went to Niagara Falls and I did another trip to VA and back and saw about 30 MPG which was good considering my speed.

I believe that the following were the major changes affecting my MPG:
1. Cleaning my MAF - removing the MAF sensor from the MAF tube and spraying the cleaner into the channel where the film sensor could be seen - I had been cleaning the thermistor on the outside of the MAF sensor that provides intake air temperature, by mistake. I have a feeling that I am not alone in not having done this right in the past. I have tried to find a picture to show the film part of the sensor, but web pictures of the sensor I found don't show it.
2. Cleaning my MAP/boost sensor on the hose from the intercooler to the throttle. I noticed an improvement in pep after this (which was done by my mechanic as it is such a pain to get to and the mounting screw was rusted).
3. Replacing my 2006 90K old upstream O2 sensor, although no codes or check engine lights were set. MPG and performance gains from this.
4. Driving in a more relaxed style, and cruising with low or no pressure on accelerator - this is also easier since the O2 change.

Earlier, I also did plugs, engine (and Cabin) air filter, IPD TCV, IPD HD coils, upper strut mount, top engine mount, IPD strut mount conversion, IPD suspension bushing inserts, ATX fluid change, steering fluid change, new battery, replaced the oil trap, front brake pads, added an additional ground wire from engine to body. I use Mobil One 5w50.

I put in a Pioneer P99RS CD head unit, an Audison 5 channel amplifier, Pioneer Stage 4 speakers in the front doors and a 12 inch sub in the trunk. The amp may be reducing my MPG due to increasing the load on the engine via the alternator but listening to music with the sunroof open is something I greatly enjoy in my life

Thanks for the discussion and insights. I will update the post if I find other related changes.