The ipd overload coils that are currently on sale fit both 740 and 940 wagons. Overload coils for 740/940 sedans, however, are seemingly no longer available. Overload coils for the 140/240 sedans are still available and are also currently on sale. Ones for the 140/240 wagons are also still available, but at regular price.

I can personally recommend them for people who haul more than the occasional heavy load, especially with wagons or heavy trailer loads. I had them in my 240 wagon and when I got my 940T wagon as my main hauling machine I immediately put them in. Keeps the ride noticeably more level which means the car handles much more normally when heavily loaded, you don't blind people at night with your raised lights, you won't bottom the suspension out as easily on bad roads and there is less bouncing around from the rear with a bucking heavy loaded trailer.

Yes, when the car is lightly loaded they are noticeably stiff over parking lot speed bumps and do not at all contribute to a soft ride in the rear, but for all the hauling I do I wouldn't trade them. If I found another set for dirt cheap I'd probably put them in our other 940 wagon, but the need for ride comfort there is just as important.

There may be cheaper heavy duty aftermarket coils, but these progressively wound overload coils were specially developed by and manufactured for ipd. In the Volvo world, ipd got their start over 50 years ago developing performance components, most famously their ipd sway bars for the 140 and 240 series, so you know these overload coils are a bit more than just thicker metal. As I recall way back when I visited ipd in Portland, they also operated an RV/trailer suspension manufacturing operation next door.

One caution, although ipd has always advertised that their overload coils add 300 lbs to your carrying capacity (which is like a 30% increase), their word won't mean anything without a DOT certificate if you're ever pulled over for an inspection because your underinflated tires were bulging out under a load of drywall on the roof and bags of concrete in the rear. What matters legally is your rated GVW and maximum permissable axle weights as determined by Volvo and DOT guidelines -ref. owner's manual specifications for your year, model, configuration and market jurisdiction.

As an aside, whereas many, including me, found that ipd sways provided much better handling on things like twisty mountain roads in the top heavy 140/240 bricks, the improvements in the better balanced 740s/940s are less noticeable. Still, having enjoyed them in my 240, I didn't hesitate to put them in my 940T along with the overload coils when I first got it. Makes twisty mountain driving a little more sure footed and likely makes a fair bit of difference when my heavily loaded trailer is trying to wag my rear end.

Just my 2 cents.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now