Toyota recommends plug replacement at 120K. I believe coils are replaced on condition (when they fail). While doing the plugs you could have the shop run a compression test.

I would also clean the mass airflow sensor on top of your air filter box. There are specific sprays for this.

Have you confirmed the low mileage the old fashioned way, divide miles driven by gallons put in?

 

check air filter, a must do every few years or lots of miles. If no codes its best to have the engine analyzed by a mechanic who can see the mixture and rich/lean running if its an issue. Largely dictated by the O2 sensors. Better than throwing money at guessing and then you know!!

 

Yes, I have been keeping track the old fashioned way. I’m going to do the plugs in the next two weeks myself and I’ll do a compression test. Also, yes, I have done the air filter about 6 months ago.

I’ll clean the MAF sensor here this weekend. Would cleaning the throttle body help at all? Should I just do it while I’m there?

 

A 4 cyl is easy. V6 a big job no knowing You can get those ELM327 OBD2 bluetooth plugs and load software on your phone some will show the fuel mixture and more.

 

When you say 'serviced trans' what does that mean? A full fluid flush or just a standard drain and fill with no internal cleaning? It's my understanding that if you did a full flush, you lost old trans fluid age with it. Sometimes transmissions tend to run better with the old stuffy still in there. If it's red, leave that blood alone. Any other color in a Toyota only really needs a standard drain and fill with OEM fluid or if you're at all worried about the old fluid in there, get REDLINE.

My 2011 Camry V6 has 250K on it and still get 28MPG freeway when I drive VERY conservatively.

Nowadays, it seems freeways are 80+mph! This change happened with CV19 and !! Defund the Police !! as I don't see many HWY Patrol out there anymore... So if you live in such an area, this could be why your MPG is lower. Maintaining this speed, my MPG drops down to about 26.

 

Weather and environment are the biggest factors in mileage. Wind but that should be obvious. Plugs won't resolve anything as severe missing would have to be present and that would throw codes and show up in drivability aspects. You got cheap gas there while we're $2.10 a litre or $9.45 Cnd Gallon. Want some Cnd Gas come north!!

 

First stop guessing and simply throwing parts at it. Maintenance and fuel are key elements here. Hs your gas formulation changed? The senile puppet in the white house is now mandating 15% to 20% ethanol. Toyota says "no way" but our guvmint wants to shove that crap down our throats. That alone can cause a severe decrease in performance. Plugs are definitely called for at this point though. Though, I doubt they alone would justify that kind of loss of MPG or performance. I would have a GOOD tech do a full analysis on it, before doing stuff willy nilly. But first be sure you're not a victim of the new gas blend

 

Ah, Ethanol. Yet another in a long list of Gullible-mint stupidity completely fueled by lobbyists and quid-pro-quo instead of science. E10 should have disappeared as soon as turbo'd everything became the norm. E85 works better there. We can still keep E but actually make it work better instead of shoving it down everyone's throat. More is always less for regular ICE. Florida has non-E and I get approx 10-15% better on the rare vacation trips. Now that Disney is WOKE, that is one less reason to vacation there... RANT / over. Peace everyone.

 

Brake drag? After a drive are your rotors evenly hot side to side? Maybe something is sticking?

 

Definitely haven’t thrown any parts whatsoever at it lol. Just getting a feel. And yeah I can do all/most repairs but I’m not expert on the subject and really don’t know/trust anyone in my area. Which sucks.

I have used the same gas for 4 years but I suppose that could have changed..for what it’s worth I live in Buffalo. I heard the whole “winter gas” theory but has continued the same in the warm spring we’ve started having.

Thanks for the input, folks. It’s all appreciated. Anyone think cleaning the throttle body is worth it (just in general and regarding mileage)?

 

you had to have changed tires at least once maybe 2x by now. what are they?

 

A lot of US gas is Top Tier Gas and makes a difference over time. Its much cleaner running. Throttle body can affect running and idle. Fuel efficiency I can't say, however its relatively easy to do cleaning the plate and outer area with a clean rag. Here we also suffer a lot less mileage in the the winter 1 to 2L more per 100km on the computer calculator of the dash. All vehicles do this. I stick to the name brand gas station & only 4 are Top Tier Gas in Canada.

 

My cars don't know the difference between no E and E10. I have tried both ways (at least on my Highlander). But our guvner is now looking at shoving E20 down our throats. Knowing full well it could wreck havoc on many people's vehicles in the process

 

^^^ the plan to force you one step closer to the glorious EV regardless of how damaging to the environment they really are. Everyone gets an EV!!! Yeah, the only way I'm in that line is through huge government incentives similar to the very recent 'Cash4Clunkers' that got many large inefficient vehicles off the road and typically traded them in for a mini-micro-mobile.

Hilarious! Maybe -- C4Cx2+freeHomeChargerUpgrade -- the real offset of EV prices will take place. Govt. can fund it by not acquiring annual 10% pay raises... Or perhaps not sending 40,000,000,000,000 (40B with zeros because politicians only go by whole number+letter to define costs / they aren't good at math or logic) to Ukraine seeing how they are an independent country and not part of NATO... It's gonna cost way more than that to restore the country after Russia is done carpet bombing it. I guess we'll be there to fix it up for the next attack like we did in Afghanistan over and over and over only to just give it all + our military gear back to the Taliban...

Dang it / I thought I was done ranting...

 

While I agree with a lot of what you all said, let’s keep the political talk out of this lol…

 

New spark plugs will help. Make sure you get either the factory Toyota ones or the OEM equivalent (such as NGK etc). I highly suggest getting them from a reputable place such as the dealer or a large auto parts store known to stock original parts. Online places such as Amazon, EBay are known to have fake counterfeit parts.