But unfortunately my 740 didn't come with an owners manual. Does anyone know what oil would be best to use in it? Any help would be appreciated!

Any other tips for this would be nice, too. Who knows how long it's been since this cars had an oil change. I know it needs one! Thanks!

 

Use any quality 10-30, or 10-30 full synthetic. I go 4,500mi on the mineral, 6,500 on the synthetic. I use MANN filters.

 

Shell Rotella all the way. It has better cleaning additives, is available in mineral and synthetic, and can be found at Walmart relatively cheap.

 

I use Mobil One from wherever I can get it cheapest, (usually Costco when they have a coupon), 10W30. Really, any major brand 10W30 will do you just fine. Rotella is a diesel oil, and I thought it only came in heavier weights....

don't use heavier oil, especially in a turbo. If you live where its really cold, you could use a 5W30 full synthetic in the winter, and it wouldn't hurt year around.

and I second the emotion on Mann filters. can be had for a quite reasonable price from ipdusa or fcpeuro. They are the full OEM spec filter, with the proper bypass, and lots of pleats.

 

I always went with 10w30 in cool climates and 10w40 in the hot summer months. Had over 400,000 on mine. I wasn't a big Mann filter with the 740 (didn't know better), but I wouldn't dare use anything else in my 850.

 

We bough our 89 740 new and it was delivered with 10W-40 in it. We still use the same weight after 330,000 miles. Change every 5,000 miles . Usually use Castrol or Valvoline. Stayed with OEM filters

 

Thanks everyone. I'll have to pick some up as soon as I can. At least now I have an idea of what to get.

 

the oil table in the 740 owners manual probably says to use 10W30 for temps from -5F to 105F, and 15W40 for temps from +5F and above (but never to use 15W40 below +5F). If you're using 10W30 and you're crossing Death Valley in the summer, just take it easy... I did that once on my motorcycle when it was 117F in the shade, one guy had his battery boil dry.

for very cold winter conditions, you can use 5W30 as long as its not above 68F.