Post oil change feeling. Placebo effect?

I don't know why but I feel like my truck has slightly more power and acceleration after a fresh oil change.

Anyone else get this feeling?

Also, is there any immediate benefit to an oil change or is it all placebo effect?

Possibly... Ages ago I had a '91 Acura Integra. I generally changed the oil every 3000 miles. The weird part was if I tried to stretch it out much past that, the gas mileage would go from its typical 30 mpg down to around 26 or 27. Change the oil - right back to 30 mpg. Everything I've read says it shouldn't have done that, but I drove that car for 150K miles and it exhibited those symptoms more than just a few times.

Oil change effect is very noticeable on motorcycles with integrated gearboxes. Less so on car engines, but there is an effect. Usually I'll notice it on the oil pressure gauge.

Yep. The car is happy. Same thing after you wash it, right?

I notice it too.

I've only noticed it once. The old oil had 16000 miles on it. (Not my van.) It made a big difference.

Its real in Gran Turismo...

Way back in the day......... (early 1980s) I was running Penzoil. I changed to Castrol GTX and the engine ran appreciably smoother and more powerful. I've never experienced the same difference from any other oil change - including going over to synthetic, but that one time it was significant.

If you go to one of them Quickie places, they also put air in the tires. It could be the air or it could be the oil...

Anyway, my Saturn goes 10,000+ miles between changes and fresh oil appears to make the car happy.

Increased lubricity = decreased friction.

If the oil was dirty or started to breakdown, it can certainly affect the power. And the fuel economy.

foxtrapper wrote: Oil change effect is very noticeable on motorcycles with integrated gearboxes. Less so on car engines, but there is an effect. Usually I'll notice it on the oil pressure gauge.

Yep, after awhile I quit paying attention to mileage, and just changed the oil in my R6 when the clutch started feeling "off."

Sometimes, it could be the placebo effect, but most of the time, you do notice a small difference. With my E36, the Vanos gets noisy when the oil has broken down, and quiets down when I change the oil. I've never heard about a vehicle picking up power, though.

I get better gas mileage after an oil change. I change at 5K with Walmart private label full synthetic.

This is exactly why I stopped running the Extended Performance oils aka European car formula, because I thought something was going wrong with the engine after 5 or 6k miles. After spending years on the oil forums, I just run the cheapest and lightest full synthetic without oil consumption and change it every 5k with no additives. The only additive approved by Mercedes for their desert cars is Chevron Techron for the fuel and I just do that with the oil change. Over 200k miles on my EG33 and still no oil consumption with a 5w-50, next step is a 10w-60 and then back to conventional. I've always wondered how much more efficient the M3 guys would be if they dropped from the 10w-60 to 0w-20. Btw, I also only use top tier gasolines which in my area are Shell and Mobil.

I"m bumping this, as we have a through discussion of oil that you guys may find interesting on our "Shop Talk" forum. Can be found here:

http://www.performanceracingoils.com/PDF/PCA_Club_Racing_News.pdf

Have your old oil tested.

It will tell you when you should change your oil.

Otherwise, I change my oil hen Ford tells me to.

Every 10K.

A viscosity change from the oil degrading might cause that. Get UOA done (NAPA FIL 4077, $14+shipping) and see what the difference is.

In reply to svxsti:

Tell me more about the euro formula, my little brothers e39 went to an indy shop for something and they freaked out that he wasnt running euro formula $40 a gallon oil. Well it leaked oil bad and he kept pouring that expensive oil in it. Ive since fixed the leak and its a greak car but im not sure whats so important about the euro formula and you seem to have some insight on the matter.

On topic, the hydraulic lash adjusters tick on my miata at 2k miles unless it's rotella then it last almost 4k. I noticed it a bit slower when I originally switched to rotella t (internet cure for the tick) but have sense switched to rotella t6 and she seems to like it, still not ticking.

Only once did I change oil in something and it legitimate ran better, 80s model f150 5.0 that hadnt had the oil changed in 10 years

i have had to change the idle speed on a couple of my carbureted cars after changing the oil- the 355 in my Nova gained 200rpm in hot idle speed when i switched from regular Valvoline 10w-30 oil to mobil 1 10w-30, and there wasn't really that many miles on the old oil when i changed it..

In reply to novaderrik:

Makes sense, many of the M1 flavors run on the light end of the viscosity range.

chiodos wrote: In reply to svxsti: Tell me more about the euro formula, my little brothers e39 went to an indy shop for something and they freaked out that he wasnt running euro formula $40 a gallon oil. Well it leaked oil bad and he kept pouring that expensive oil in it. Ive since fixed the leak and its a greak car but im not sure whats so important about the euro formula and you seem to have some insight on the matter. On topic, the hydraulic lash adjusters tick on my miata at 2k miles unless it's rotella then it last almost 4k. I noticed it a bit slower when I originally switched to rotella t (internet cure for the tick) but have sense switched to rotella t6 and she seems to like it, still not ticking. Only once did I change oil in something and it legitimate ran better, 80s model f150 5.0 that hadnt had the oil changed in 10 years

The euro oil has different specs than US/Japanese oil specs. Euro (ACEA), which is run by the manufacturers, is interested in high load/high heat specs. US/Japanese (API), which is run by the manufacturers, is interested in cold start specs.

So a 5w-30 API oil is most likely very different from a 5w-30 ACEA oil, even from the same manufacturer.

The main reason BMW and MBZ have thier own specs is for long life. So if you change it every 5K instead of 10-15K like they want, it's a moot point.

Sweet baby jaysus. Is this another oil thread? Off with yer heads!

I've noticed the same thing many times. I dumped a little left over white gas in my pickup's tank the other day and I swear it idled smoother.

For a while everybody wanted the green cap (GC) Castrol which was made in Germany.

spitfirebill wrote: I've noticed the same thing many times. I dumped a little left over white gas in my pickup's tank the other day and I swear it idled smoother.

Where did you find the white gas ?