MPG Lower after new plugs? - Toyota Nation Forum : Toyota Car and Truck Forums

BlueFusion6851 · 01-25-2006, 08:15 PM

Hello there. I'm going to be brief. We had our Camry in for service, we had our sparkplugs replaced and on the last tank of gas we averaged about 16.7 mpg... usually we get around 20-22... Is there something connected with newer plugs and worse mileage or vice-versa? The mileage was a mix of highway and city driving for both... I don't quite know what else could be screwing this up... cause 4 less mpg was about 52 less miles (a trip to work and back for me) I'd like to know as to what might have caused this?

Thanks

95WhiteCamry · 01-25-2006, 08:34 PM

if i remember correctly cold weather conditions really decrease fuel economy so that could be your problem.
this is a long shot but maybe the plus are a bit screwy? poorly gapped, poor quality, something of the like. and didn't you get other things done while serviced? could be something from that too.

BlueFusion6851 · 01-25-2006, 08:52 PM

Along with the plugs we had the Distributor O-Ring and Intake gasket replaced. We didn't want to replace the powersteering pump and rack and pinion yet... also they found the tranny speed sensor leaking as well. I don't think any of those things would cause bad MPG.

touringcamry · 01-25-2006, 10:23 PM

Where did you have your vehicle serviced?

My uncle had it done at a local shop and had a similar problem. Turned out the shop put in the wrong type of spark plugs. I don't know if they weren't platinums what was wrong with them. He took it to the dealer and the replaced with OE plugs and the car was fine afterwards.

V6LE_CAMRY · 01-25-2006, 10:41 PM

The shop could of putten bad plugs like boch platinum type and others. The recomended brand for toyota is NGK. Check the name brand of the plugs. If they are NGK they probably werent gapped or misgapped.

Grayguy · 01-26-2006, 12:10 AM

The same thing happened to me. I put in the NGK plugs, and went from 29 down to 22. I didn't do anything with the gaps, cause people told me here I didn't need to. The only thing is, that I did this right before a really cold snap, so I'm not sure if it's the plugs or weather. Guess I'll find out in a couple months when it warms up...

Den · 01-26-2006, 05:10 AM

This is getting interesting!! I want to know what is the Gap doing as well. I always thought that the new plugs will have a right gap!! BUMP this to top and discuss about it!

TBayToyotaBoy · 01-26-2006, 05:24 AM

Cheap/incorrect plugs and/or wires will screw your mpg ratings, and cold weather definitely has an adverse effect on mileage. Look at the invoice the mechanic gave you, and check for part numbers. Go to a parts store you trust and ask to ensure the correct parts were installed.

Sometimes cheap aftermarket parts aren't worth the savings in initial cost. I replaced my Denso (Toyota) distributor cap and Sumitomo wires with Niehoff parts and my car was NOT impressed. For future parts, ask here for peoples' opinions and experiences before going into the garage. If there's a part out there, someone here has tried it!

vwsteve · 01-26-2006, 11:17 AM

I have had Bosch in my car for 30000 miles and have seen no drop in mpg. make sure the plug you are using is the correct listing fir the car. The heat range being off can cause problems. At my oil changes (3000 miles) the oil still looks clean, so the plugs must be working as to not getting any soot in the oil from poor combustion. I use 10w30 valvoline oil and a Toyota filter. may try checking the air filter that will also cause drop in milage. inflate the tire to the proper psi ( we see under inflated tire all the time) and double check all their work. some shops will use the cheapest parts to increase proffits so they could of put some 99 cent champians in the car.

BlueFusion6851 · 01-26-2006, 05:57 PM

Well... It was serviced at St. Cloud Toyota. They used Toyota Platinum plugs. They had a stand with their platinum plugs compared to somebody else's. The car runs great, just gets worse gas mileage thats all.

amerikim · 01-26-2006, 07:58 PM

Ethanol added to gas by law during winter months in Portland, OR.
16.9 mpg today. That shit is terrible for performance.

BlueFusion6851 · 01-26-2006, 09:44 PM

I know what ya mean. I liked having a tank run around 25-26 mpg... damn those days are over.

BlueFusion6851 · 01-27-2006, 10:38 PM

*bump*

TBayToyotaBoy · 01-28-2006, 08:47 PM

The worst experience I ever had was with Champion plugs. Yeah, I said Champion. Parts stores always have to special order for me, cuz there aren't any of these cars here. I was waiting for NGKs to come in and decided to try the el-cheapos (the product reference manual actually listed Chmpions for my Camry). There's a reason they're meant for lawn mowers...my V6 ran exactly like a two-stroke.

Interesting thought about the Ethanol addition in winter...I should check it out, it would help explain my sorry-ass mileage every January/Feb.

DFBonnett · 01-29-2006, 09:47 AM

Quote:

Originally Posted by Den

This is getting interesting!! I want to know what is the Gap doing as well. I always thought that the new plugs will have a right gap!! BUMP this to top and discuss about it!

Usually they are gapped correctly right out of the box. Sometimes one or two may be off, usually narrower, I suspect from the box being dropped sometime between manufacture and installation. *ALWAYS* verify gap before installation.

Re: the OPS problem....
It is possible a plug wire got damaged in the process of removing them to install the new plugs. This is very common with wires that have some time and mileage on them. They tend to get a bit brittle from heat and age. You might wish to check out that possibility.