# Full Synthetic vs. Synthetic Blend



## DeanHensler (Jul 2, 2012)

I just picked up a 2012 Chevy Cruze LT with 52,000 miles on it. It needs to have the oil changed and I'm a do it yourself kind of guy, always changing my own oil. I've read the manual about the Dexos1 oil requirement and I get that. My question is about using a full synthetic vs a synthetic blend. All of my previous vehicles just used standard 5w-30 oil so I don't know much about synthetic. Which is better for the cruze, a full or blend and why?

Thanks.


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## bduffey723 (Apr 30, 2012)

I use full synthetic for longer intervals and more stable viscosity at low temperatures.


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## bduffey723 (Apr 30, 2012)

bduffey723 said:


> I use full synthetic for longer intervals and more stable viscosity at low temperatures.


Also, IIRC, the blend has just a small percentage of synthetic in it so it really is a negligible amount better compared to conventional oil. Synthetic has more uniform molecules than conventional. Unless your car has a lot of miles on it, I would always recommend full synthetic.


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## blk88verde (Apr 30, 2011)

Definitely use full synthetic, these engines are designed to run hot for fuel economy and you have a turbo that stresses the oil. I have used mobil 1 since 1000 miles on the odometer. I have changed the mobil 1 between 7 - 7.5K miles. For my latest oil change @ I have switched to Royal Purple.


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## cruze01 (Mar 25, 2011)

Go to bobistheoilguy.com you'll learn all you could ever want to know about oil! I recommend full synthetic.


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## sciphi (Aug 26, 2011)

Full synthetic. In a 1.4T, using a synthetic blend is cheaping out now while asking for trouble later. 

If you go to Bobistheoilguy, look for my used oil analyses, and those of other Cruzes.


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## GoldenCruze (Dec 18, 2011)

The main advantage to synthetic oils is resistance to breakdown due to heat.

I went with Mobile 1 from my first oil change.


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## weimerrj (Dec 4, 2011)

IIRC, the GM branded oil at the dealership is a blend, so it should be fine. That being said, Full synthetic is better, and not much more expensive than blends anymore. There's also the question of availability. Full synthetic Dexos oils are definitely easier to find than the blends in my area, so I get full synthetic. Peak sells a full synthetic Dexos oil that's the same price (or less) as everyone else's blend.

I also look for the ~$30 oil change specials (5 qt + filter).


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## Blue Angel (Feb 18, 2011)

I switched out the factory fill (Dexos1 syn-blend) for Mobil1 5W-30 at 4k kms (~2.5k miles), and recently had mu first scheduled oil change and am staying with Mobil1. I'm able to get Mobil1 on sale for a reasonable price (on sale right now at Canadian Tire, $33 for 5.4L). It meets the Dexos1 requirements, and probably exceeds them in many areas.

My last daily driven car was an '01 Saturn SC2 coupe. In that car, a fresh oil change with conventional oil would see the oil level staying dead consistent for the first ~5k kms and then dropping about 1L/2k kms after that. Once I switched to Mobil1, levels stayed much more consistent. The Oil Life Monitor was suggesting oil changes every 10-12k kms (6.2-7.5k miles) and I only had to add about 1L of Mobil1 between oil changes to keep it topped up. Compare that to 3-4L of conventional oil top-ups between changes… the engine only held about 4.5L!

Since the conventional oil started leaking past the rings and burning off after about 5k kms, I'm pretty certain it was losing viscosity. Based on that and the long-ish oil change intervals suggested by the OLM I determined that full synthetic was the way to go. The much more stable oil levels between changes confirmed that for me.

I'm not sure which full synthetic oil is currently the "best", but from the little bit I've read Mobil1 is "one of the best" full synthetics. It's also reasonable priced (when on sale 30% off) and easy to get. My local Mr. Lube charges $29 for an oil/filter change with customer supplied oil and filter, so with an AC Delco filter ($4) and my own oil (~$27) I get a full synthetic oil change with an OEM filter and Mobil1 for about $60+tax. Most places charge far more than that for a "synthetic oil change" and in most cases you have no idea what oil and which filter they're using.

Even a regular oil change costs over $40 with tax. Since I plan to keep the car for a long time this small premium is worth it.


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