I have a 2007 Volvo s40 2.4i and it has 70,000 miles on the odometer. I have kept up on the maintenance and I drive somewhat aggressively. I have noticed over the last year that my performance such as acceleration has seemed to decrease. Its not a drastic decrease but the car doesn't give that acceleration punch like it has in the past. Recently over the summer I had my spark plugs changed, and the air filter replaced. I'm not sure what could be the reason behind the dropped performance. Does anyone know what I'm talking about? I want to know what can be done to restore my s40 back to normal swift acceleration. Let me know if more details are needed. Thanks

 

It could be in you mind you simply got used to it.Time to upgrade.
On a more serious note I see 3 reason why you might losing performance.Fuel quality the air filter and the spark plugs.Air filter I dont have to explain.The other two could cause problems if you are having pre-detonation issue caused by them.When it happens the ECU will turn the ignition timing back to counter act the knocking.
Check the plugs if they are the correct heat range and what the manual say you should have.Stay away from cheapo ones as well multi electrode ones.
See if the fuel filter was ever replaced.Lean mixture caused by clogged filter also will cause pre-detonation tho this also should throw a code for misfire.

 

Without knowing much about it, a guess would be water in your gas. Maybe get some Heet. I tried getting gas from a place that said ethanol free and my car just didn't seem right after that. Got some Heet and all was well again.

 

What grade fuel do you run?

 

By nature we are hoarders. How much junk is in the car/trunk?

 

Thanks for all the answers. I run premium gasoline, 93. And I don't have much in my trunk. I believe I just need to upgrade so I'm going to look forward to doing that.

 

If you like off the line speed/torque, get a turbo.

 

In your opinion is 70,000 miles on the dash a lot for a small S40? I'm about to take a trip from New York down to North Carolina and I was wondering what kind of car prep should I do to make sure I'll have no problems with the drive? What are your recommendations?

 

Check fluid levels, get a tank of gas and go. No, 70,000 is NOTHING. I have 220,000 on mine and if I had a desire to go to NC (750 miles) tonight, I would clean out a little junk, gas and go. The only fluid I would check is oil.

Matter of fact, when I purchased this car, the seller told me that it had a bad tranny and I told him to meet me at the airport in Providance and when he did, I immediately headed to Little Rock AR. 1,500 Miles away. I checked fluids, belts, tires, made sure I had a spare, and I took off. The tranny fluid was so bad that on my way out of town, I stopped by Sears and got a tool to take the tranny plug out and I drained and refilled the tranny in their parking lot and took off. Got 150 miles down the road and stopped by FCP, did another drain and fill in their parking lot. Stopped in Bultimore, did another drian and fill at a city park and the tranny was doing much better.

Cars have no idea how far they are being driven. 30 Miles or 400 makes no difference to them, they don't know. All they know is warm and cold. They will start cold and start warm or they won't. If the car is leaking coolant or oil, you might want to get that fixed before you hit the road. I don't like driving across town with a coolant leak. My daughter drove 1200 miles with a bad head gasket. Just stopped to keep coolant in the car. My mom drove from Pittsburgh to Rockport SC with a cracked block, just had to make sure she didn't run out of oil. The car my mom has now burns 1 quart of oil every 500 miles. She just has to top off the oil when she gets gas, at least 1/2 quart per tank. Kinda like a lawn mower.

I suspect that your car is in great shape compared to theirs.

 

A maintained Volvo can do 300,000 miles easy. The car I drive daily, my 850 has 220,000 on it. I took it to Albuquerque a few weeks ago, 865 miles each way. That was it's 2nd trip to Alubquerque and it also went to Charlotte once or twice this year (750 each way). I had a 740 GLE that had over 400,000 miles on it. I use to run it to Albuquerque, Pittsburgh, etc., all the time. I had to get that car towed twice for the same reason, it was running out of gas. A driveway collapsed under it one day and it landed on the fuel tank. When that happened it bent the fuel sending unit and caused the car to run out of gas a couple of times because it wasn't picking up the gas off the bottom of the tank.

I had a 960 that got towed once, after I drove it down the freeway on 2 wheels (I hit a tire in the road). Knocked a wheel off of it.

My point is, cars seldom break down on the road. Here is a short list of the main causes cars break down on the road and need towed:

- Flat and NO spare.
- Old water hose breaks and the car over heats. (Usually on cars that are over 10 years old and/or with more than 150,000 miles on it.
- Car runs out of gas.
- Battery dies because it's old.
- Fan or timing belt breaks because it was so old and cracked up it was over due it's time change.
- Fuel pump fails. Main reason they do, car has over 250,000 miles and/or it has been run out of gas.
- Idler seizes up on the freeway and breaks the belt (or some other item like alternator). Owner has likely ignored the squealing noise for months.

 

I don't think you have anything to be of any real concern. You mentioned that you tend to drive your car a bit aggressively, and after 70k miles, cars are naturally going to lose a degree of their compression capability, so minor acceleration decrease isnt anything to be concerned about. Just keep up what you're doing with the maintenance and using premium fuel and you'll do fine. As for the upcoming road trip, simply make sure your fluid levels are all where they need to be (transmission, brake, oil, coolant) and check the air pressure in your tires and you're ready to roll. As a habit, when I am taking a road trip that is any more than 300 miles, I like to change my oil and have my tires rotated before heading out, but this is just a personal preference.
As for the upgrade, you do seem to be a bit of a self-proclaimed performance junkie, so I'd definitely go for the S40 or S60 T5!