Engine oil VALVOLINE or PENNZOIL

I use pennzoil euro spec, I only go through about a quart between 5k oil changes.

I've been alternating between the OE Castrol (with the free maintenance) and Pennzoil Ultra Euro 5W-40 (502 compliant and recognized/certified by Audi/VW) in 5,000 mile intervals. I've had both tested, and the TBN is higher on the Pennzoil and the viscosity always perfect (Castrol tends to read thinner than 5w-40 on the samples I've sent in for analysis).

I use 0W-20 Pennzoil Platinum for our 2013 Accord Sport.

My car runs full synthetic, no additives. I find a 2.0 engine oil filter mount swap(from cartridge to screw on), royal purple filter, and penzoil ultra/platinum are an amazing combination.

Anyway, when I had my Passat 1.8T and sludge issues were the big fad, my oil of choice was Valvoline Synpower 5w40. It met 502 and was not a synthetic blend but rather a real synthetic.

I use valvoline because it's common and it does the job. My auto mechanics instructor also recommended it because he said most of the engines he'd taken apart that had run valvoline looked pretty crud free.

I use Pennzoil Ultra 5W-40 European formula in both of my GTI's and use only oem filters (which are very good btw).

Strictly anecdotal, but at 56,000 I switched from the usual suspect Castrol to Valvoline Synpower. Engine starts more smoothly and observed mileage on highway has gone from approx 30 to approx 34 mpg.

I use 20/50 Valvoline year round....

That is my personal favorite so far. Use or burn less than anything else I have tried, and I swear the engine sounds quieter. Previously used Castrol, Amsoil, Mobil 1.