Could not changing the oil in 8 thousand miles cause severe engine trouble?

Not changing the oil and not having oil are 2 different things. Not changing the oil on those kind of miles will sludge up an engine in the long run leaving you in the same place you are now. Also not changing it, especially in cold weather will leave moisture in the oil and this is another engine killer. Many of the Saturn's are oil eaters. I have seen many them use a few quarts between a 3000 mile oil change.

It won't be severe if you have only missed a few oil changes... but... it takes life away from your engine. Engine oil lubricates and protects all of the moving parts, when the oil is dirty it will cause the parts to wear much faster. I've seen people who haven't changed their oil in over a year and it's black... I also saw a vehicle that didn't have an oil change in 5 years. The oil was as black as black can get and came out like tar, we took off the oil pan and it was just sludge. Not pretty. Take care of your vehicle and it will take care of you. People who get regular oil changes prolong the life of their engines.

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Actually it is probably fine if all your trips exceed 10 miles and you don't idle to much. Most manufacturers recommend 7,500 mile intervals for highway type driving. I own an Audi Quattro Turbo and a 05 Bonneville GXP (300 hp Northstar v8). Both cars use Mobile one 0w40 synthetic oil. With the Audi I had used oil analysis done and found that 10,000 mile changes were fine and still had some reserve, could probably go 12k without issue. I have not done that on the Bonneville as that is my toy and doesn't get used much. I chance the oil when the GM oil life monitor tells me to. It varies from 4500-8000 miles usually because I have reached the one year requirement.

I summary I would not be concerned at all. If you are an average user with dinosaur oil than change it every 5k, synthetic 7500 unless you confirm you can go further through testing the drain oil.

Kevin,