Hey everyone,

I just bought a 2006 HHR LT 2.4 with the 2.4 motor a few hours ago, it has 132k miles. There was records for oil changes almost every 3k miles consistently in the carfax up yo about 47k miles on the car with the first owner in the carfax. The second owner must of had oil changes where carfax doesn't hear about it.

I purchased this car for work. I work just about everyday and its a 60 mile round trip. So thats 1800 miles a day but probably a little less, maybe like 1500.

So my question is if conventional oil has been used its whole life would it be safe to switch over to mobil 1 full synthetic?

I have read before that it can cause leaks in the valves or something. Not really sure but Its due for an oil change and I wanna make the switch unless someone advises against it.

 

I have heard some talk like that before. I myself do not believe the stories.

I switch my suburban to mobile one at 145,000 miles it now has 230,000 on it now with no adverse affects. The only oil leak it has is from a rusty oil pan.

Mobile one oil is all I use in all my vehicles. I once asked an auto engine engineer which was better synthetic or regular oil? His response was synthetic oil is made in a lab a is deigned to be a lubricant from the start. Regular oil is pulled from the ground,refined and turned into a lubricant.

That was good for me.

 

I tried switching to synthetic at about 100,000 miles (maybe a bit less than that) - up until that point our 2006 2.4L hardly used a drop between 4-5000 mile oil changes (maybe a quarter of a quart - if that).

Anyways I changed to synthetic at high mileage, along with a oil filter change and about 2000 miles later checked the oil level as I was about to go on a weekend trip, and was quite shocked to find it was down over a quart!!!! I topped it up for the trip, and sure enough it was down a good quarter of a quart after the 400-500 mile trip.

I dumped the synthetic and went back to conventional as soon as I could - it took about another 8000 miles on conventional for the oil consumption to ALMOST return back to normal.

I do my own oil/filter changes, and am fairly meticulous about making sure there are no leaks and that the oil is topped up properly. So I am very sure it was not due to "operator error".

It did not leak a drop at all - and I never noticed any out the tail pipe. Needless to say I won't go back to synthetic on this engine.

 

I have found that Mobil1 and some off-brands (probably repackaged Mobil1) tend to burn.

You can switch, no problem

IF you switch to a "high mileage" motor oil, you should not switch back to regular. This is because the "high mileage" formulations swell seals. If you switch back the seals un swell and cause leaks.

All of those 40 year old horror stories are false.

 

I have experience to confirm that sort of thing, too.

My last car (different engine entirely) would blow any synthetic out through the PCV - more than I liked to see. Pennzoil Platinum did it the least, but I used it for lubricant reasons, and just kept tabs on the level weekly (~500 miles in my case). Any time I was headed for an autocross or other event where I was going to be up in the revs, I slightly over-filled it. Blowing oil through the PCV also made the throttle body a mess, and I had to clean it about every 10k or suffer idle problems. Haven't seen that issue since, but I think the SS was designed for synthetic. I use Mobil 1 High Mileage now, and don't waver at all. At 104K now, it's cheap protection.

Don't know that that cleared anything up, though.

 

I would go with the blend and had zero problems... You get the best of both worlds ... With winter coming up here in chitown ...

 

I had Mobil 1 Full Synth, and when I got to 25% OLI, I started hearing a very airy sound under the hood (98,xxx miles at the time).. Switched off that. I believe I have Semi-Synth now and it's much better.

 

I may have to retract my statement about not believing the story's.

You guys on here are far more credible then some of the stories I have heard with synth oils.

I have used mobile one in all my cars with no problems however the suburban was high miles when I bought it, I did change to mobile one and it does burn some oil.

A engine with 145,000 miles that burns a little oil, I just never gave it a thought that it might be the mobile one oil being the problem.

 

I think luck sometimes has something to do with it - didn't work well for me, but others may find it works fantastic for them.

When synthetics were being raved about for motorcycles back in the 80's saying that it made the tranny shift real smooth - "no more klunking" - I tried it and it made absolutely no difference on my bike at all. So back to conventional on the next oil change. Luck of the draw?

 

I have used synthetic oils in all my cars for about ten years now. I buy it when its on sale, pay about $25 for a five litre container and pay my mechanic $20 to do the oil change, so my total cost is $45. Instead of changing the oil every 3,000 miles/5,000 km, I change it every 6,000 km/10,000 km, so overall it doesn't cost me more than regular oil and its better for the car.