Haha, so much sludge! 4-5k at the most, I even change my gear oil about every 6 months.

Most I have gone is about 3500 miles. My hot rods don't usually get to 3000 in the 8 month driving season, but I change the oil every fall in them for storage. I once pulled the valve cover off an AMC 4.2L six and found the sludge was so thinck you couldn't even see the rocker arms! The oil was almost molded into the shape of the valve cover itself!

depends, if I had driven a lot then around 4.5k if not every 3-4 months depending how long it sat.

I burn so much oil i rarely need an oil change.. just keep adding more! But, honestly... I end up changing it for one reason or another every 100 miles or so *sad face* It just put-puts me from neighboring town to neighboring town anyway.. i ONCE went 15 miles and back!

I think I have gone about 3200 but I try to keep to 3 months or 3k miles. Lots of dust and I do enough town driving where I think its a good call. It might be overkill but I sure as hell figure its not hurting anything.

I personally have gone about 5-6k between a few oil changes, but i went through a friends motor in his truck and he didn't change it for 10k on the break in oil (needless to say the truck burns a little oil now)

5000 kms

I've gone about 8 or 9k.

6,000 miles...

I have a 30-year old JDM and I use it everyday for everything and I do at least two 15-hour road trips a year so I do my maintenance every six months. But someone referred me to this oil treatment thing that's supposed to rejuvenate the existing oil and you just need to add oil to get the right level and you're good to go-no oil or filter change necessary. I know, it's a bad idea. I'm pass my 6th month and already. I'll change the oil after 12 months and see how the thing performed. I mean, it it saves me a lot of buck from oil changes then it worth the shot right. We'll see.

I go 10k on my Ford Contour... took the valve cover off and found no sludge at 140k miles. Plus do the math: oil and filter $30 every 3k up to let's say 100k miles comes to at least $1000. You can buy an engine for that! So I'll take my chances at 10k thanks.

when i was a teenager, i went about a year in my 4runner without an oil change. i was very stupid.

I have gone around 4000 miles, but that is the worst. Amsoil morons are the worst. Some go the full 25,000 miles Amsoil claims... NO WAY IN HELL! I have worked for GM, Toyota, and Ford and can tell you going too long too often can void an engine warranty, as it should.

Every 2k with the Formula. Whenever in the Camry.

I used to be an every 3K kind of guy. But after watching videos of the change in viscosity from 3K miles to 5K miles, there's almost no difference. So I always do 5K miles now, maybe 5.5K if I'm being lazy!

Every 5k miles usually.

I'm at my dealer right now getting an oil change and this is the longest I've ever left it. 8000km.

If you are going over 5,000 miles between oil changes, use a decent product like Mobil 1 or Amsoil!

I go every 8k-10k miles on both my cars, i will admit that I run full-synthetic as well, i figured the added price allows me to go a bit farther.

I go about 4,000 to 4,500, but I don't drive my truck regularly anymore. So, I may get the oil changed about every 6 months or so. As far as everything else goes; I try to stay on track with the maintenance. I want this truck to last as long as it can.

I'm at 2500mi on my 95 Jeep. It's got just under 200K so it seems to work. The other fluids not so much. brake-not since i've been driving it. rear end-once. power steering-after the new pump, so...once. transmission-leaks enough that i feel like adding a qt a month is like changing it.