This post may sound like I’m a Pennzoil associate, however this is simply a data point for anyone that is interested/has tried the Pennzoil Ultra Platinum Full Synthetic 5W-30 in their H3.

My Vehicle:
-2007 Hummer H3 Base - 131k miles
-315/75R16 BFG KO2 A/T - 38 psi (fairly worn, but still have probably 10k miles left on them).
-Aisin AR5 Manual Transmission
-Grill Guard & Winch mounted on front.
-87 octane fuel
- 2x new wheel-hub bearings and all driveline fluids changed with full synthetic fluids.

My speedometer is not corrected for the larger tires; I always take the odometer reading and increase by 8% to account for the larger tires. I have read in a different post that 9% (going from a 265/75/16 tire, to a 315/75/16 tire) is also acceptable, however the treads on my BFG tires are fairly worn down, so I use a more conservative estimate of 8%.

Before trying the Ultra Platinum, I usually ran Pennzoil Full Synthetic 5W-30 (not the platinum series). When using that oil, the most I had ever gotten on a tank of fuel was about 16.8 mpg, which was driving through (flat) rural Mississippi, coming from Arkansas, 55-65mph the entire time, almost no stopping, and the air conditioning off almost the entire trip minus a few short durations to cool things down. I could absolutely never break 17 mpg.

Usually I average somewhere around 16-16.5 on long distance trips, 14.5 being the worst out of them all (20-30mph headwind for ~200 miles).

I just switched to the Pennzoil Ultra Platinum, and on my very first trip (with the new oil) from Meridian MS to Panama City FL, the odometer read 264.4 miles (285 miles when accounted for the 8% increase), and only used 15.7 gallons of fuel when filled up at the pump, yielding just over 18 mpg. This was in a much hotter temperature of 80F, so you could argue there was less aerodynamic drag than my Arkansas trip (~60F), however I also had the A/C on the entire duration this time around, which was not the case on my Arkansas trip. Additionally, this was not a constant 50-60mph cruise control for 285 miles of driving either; it was more of a rolling hills profile driving through AL (a decent amount of speeding up/slowing down), with two full stops along the way for food/drinks, and a decent amount of traffic lights as well.

To sum it up, although not quite a true apples-apples comparison, I was really impressed with the performance of my H3 with the Ultra Platinum Full Synthetic oil today, and it appears to have given my H3 about a 1 mpg increase on the highway over the Pennzoil Full Synthetic oil.

I will be testing again this Sunday on my trip home back to Meridian, except I will be taking the interstate for a majority of the trip (65-70mph) to really put the car to the test. If anyone is interested, I can post the results on here, to see if perhaps this 18 mpg was simply a fluke/one-off.

Hope everyone is doing well and has a great weekend; spears accepted.

 

Yes, please post results of second test.

 

Just got home a few hours ago from my trip from Panama City FL to Meridian MS. Total Trip length was 307.3 on the odometer; an 8% increase to account for the larger BFG 315/75/16 tires is 331.9 miles. Total fuel used was 18.53 gallons (filled up at the pump), or approximately 17.9 miles per gallon, very close to the 18 mpg I got on the trip down.

More specifically; the first 30 miles was a lot of 30-40 mph while going through plenty of traffic lights (many of which I hit the red lights on, and had to stop). The next 30 miles was 50-60mph on a county highway at a pretty steady pace with almost no stops. After this, I did stop at a Lowes very briefly, then continued on I-10 for about 130 miles at a speed of around 70 mph with the cruise control on. I then made a second stop for some food, then continued for the next 70 miles at a speed of 50-60 mph, followed by another 70 miles at a speed of 65 mph. The last ~7 miles was on a county highway going 40-50 mph which got me home. Air conditioning was kept on pretty much the entire journey, and the ambient air temperature was about 80F throughout.

To summarize, my trip down to FL achieved 18 mpg, and my trip back averaged 17.9. I can now say with some confidence that this was not a fluke with the Ultra Platinum oil, and that it gave a pretty good boost to my fuel economy.

One thing I did forget to mention in my first post, was that the Pennzoil Ultra Platinum oil does not have the GM Dexos certification labeled on it. Ironically, the less expensive Pennzoil Platinum (one step down from Ultra Platinum) does have this certification; not sure if this would be a dealbreaker for anyone out there, but it’s worth noting.

Regardless though; I achieved the highest fuel economy so far in my H3 with the Pennzoil Ultra Platinum 5W-30.

Hope this helped someone out there; thank you for reading and have a great week ahead!