Pennzoil lowering gas mileage?!

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Nov 26, 2008
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My wife has an '07 Acura TSX. The first oil change I did myself and her gas mileage dropped off a couple miles per gallon. The next one we took it to the dealer and her gas mileage came back. I just changed it again, and already she says it has dropped off a little. I couldn't imagine the dealer using synthetic, but I'm starting to wonder. Anyone else had Pennzoil lower the gas mileage a couple miles per gallon after using a different oil?
 
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Never heard of or documented any such thing W/PP. chevro might be on to something.
 
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Illinois
If you are using the same wt. oil in dino or synth no matter what the brand your mileage will not be enough difference to notice. Now synth oil may show .5 MPG or so over dino again in the same wt. That has been my experience.
 

JHZR2

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Im noticing that GC is causing a definite drop in my saab 9-3 compared to SSO (which is an obvious thing) and M1 0w-40 when new. The drop compared to 0w-40 is what suprises me. The thing is, it is a multivariate problem - metalurgy vs. friction modification vs viscosity vs. whatever else... I always drive long highway, so that is out of the equation for the most part, but there are so many other things, including biggies like AC loading, that it is tough to say. Are you sure the same grade was always used???
 
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I don't have access to Acura data, but the closest oil data I could find is for '07 Accords. 5W-20 is recommended for both L4 & V6 '07 Accord engines. Give your Acura dealer a visit and ask them what oil is recommended for your engine. They should have a reference card or they can look it up on the Acura service website. There is a chance that the LOF tech is using 5W-20 for everything, and not using for the correct oil grade for your car.
 
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 Originally Posted By: ProfPS
There is a chance that the LOF tech is using 5W-20 for everything, and not using for the correct oil grade for your car.
I'll bet that's it. When I owned a Ford years ago the dealer put 10w30 in everything regardless of the spec.
 

crazymagman

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Acura dealer was putting 5W20 instead of the recommended 5W30, so that might explain the little bit better mileage.
 
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Last week I received a shipment of Acura service manuals. The 04-08 TSX manual spec's 5W-30 and the 07-08 MDX manual spec's 5W-20 for the same engine 3.5L engine block. When I spent time earlier this summer at a Honda training center, that's when I found out about Honda's oil reference card. The only Honda that spec's 10W-30 is the S2000. Other than that one, it can vary between 5W-20 and 5W-30.
 
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Oklahoma
Originally Posted By: ProfPS
Last week I received a shipment of Acura service manuals. The 04-08 TSX manual spec's 5W-30 and the 07-08 MDX manual spec's 5W-20 for the same engine 3.5L engine block. When I spent time earlier this summer at a Honda training center, that's when I found out about Honda's oil reference card. The only Honda that spec's 10W-30 is the S2000. Other than that one, it can vary between 5W-20 and 5W-30.
The TSX of 2004-9 was only available with the 2.4 LT4. The MDX has only been available with the V6. The 2010 TSX is the first model year available with the V6. The S2000 is such a different beast that 10W/30 seems prudent and even then I would run a good synthetic 10W/30 like RL.
 

FZ1

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Just ask the dealer what weight and brand they are using in bulk oil. It can change from time to time if they get a better buy on a different brand.
 
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I would suggest that where you get your fuel has more to do with it then the oil you are using! My local joint buys what is left over from the bigger fuel companies in the area.Depending on which companies additives where put into the tanker when filling it makes a huge difference in fuel economy. Most fuel int he USA is all the same other then octane each brand though will add it's own propitiatory additive package. Their are some exceptions but not many. Are you useing Dino or Synthetic? Does she drive the same route all the time? Does she always run the air, never run the air,defrost, ever idle for long periods of time etc??????
 
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Starting in 09, the TSX has the exact same k24 (z3) as the Accord 4 cyl and therefore it is a 5w20 oil user. There is hp differences but it is due to ECU tuning...the engine itself is the same. The 1st gen TSX (up to 08) is the k24a2 and is much more performance oriented than other k24's so the 5w30 makes sense.
 
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